Hello everyone
I made this guide to try to answer the question of which tank is best for you and your playstyle.
If you find any mistakes or have a different view, I am happy to listen to your feedback and correct and/or improve this guide accordingly.
First some general concepts :
Tank stats : Armor is important for a tank, but since Health is more expensive to train, and helps both against physical and magical damage, Health is even more important. So purely stat wise, if a tank has High Health and Medium Armor, he would be tougher than a tank with Medium Health and High Armor, especially since you could cheaply train for more Armor and have overall better stats.
Furthermore the Classicifaction of the Tanks (from Heavy to Medium-Light) is based on it's stats. Just as on many sites the Classification between Defensive, Balanced and Offensive is based on the stats even though those Classifications are not always consistent.
Example Spec : I made an optimized example spec for each pet with max stats and abilities. Obviously your choices might be different and as good or better than my example. But at least you will get a good idea what your Tank specced pet may look like. I don't list it below, but my example specs take Howl 7 ( costs no points, but is ofc imperative ) and and all Resists at rank 1 ( 5 points each ) into account. So if you are playing around with a Pet calculator, make sure you include these as well.
Attack speed ( AS ) : Most pet families have some specific versions of pets that have faster Attack speed. While the base damage will remain the same since slower Attack speed pets will hit harder per hit, faster Attack speed has 3 main benefits :
- More reliable Agro compared to slower Attack speed pets.
- Possibly higher overall DPS due to more chances to Critical Strike which procs Frenzy more (if you specced it) which means more Agro.
- More interrupts against casters in PvP, this is of course not a facter when tanking.
- Below I list the best possible Attack Speed each pet Family can get. I have added confirmation status :
Unconfirmed = not all my Sources have confirmed the information
Conflict = some sources conflict with others
Confirmed = All my sources say the same, or I have confirmed them myself
My sources are : Petopia.com - Classic-Pets.com - Vanillawowdb.com - The confirmation of other players - My personal confirmation.
My goal is to verify all the unconfirmed and conflicts myself and update the list accordingly.
Resists : Since all the resists are the same across the board, I do not talk about it much here. Obviously they can be quite important, so just remember you might want to put some points in them when training your pet 
Other differences between pets :
Please note that as of Classic's release all the other special differences between pets are normalized. So each pet in a familiy is the same as another pet of the same family (including stats, abilities and damage type), with Attack Speed being the only exception.
Some examples of normalized pets are :
- Lupos (Wolf), which had Shadow damage during early Vanilla. This is replaced with Normal damage in Classic.
- King Bangalash (Tiger), which had Cobra reflexes during mid-Vanilla. This is removed in Classic.
Heavy Tanks
Bear
Classification = Defensive
(Official Classification = Defensive)
Very High Health (1.08), Medium Armor (1.05), Low Damage (0.91), Fast Attack speed (1.3 - Unconfirmed).
Level 60 optimized example spec : Stamina 7 / HP = 3506 / Armor 9 / Armor = 5014 / Bite 8 / Claw 8
Stats : They have the highest Health of all the Tanks and still good enough Armor, this is the strongest tank stat wise.
Abilities : They have no particular tank ability but they have 2 DPS abilities, Bite and Claw, which helps offset their base Low Damage somewhat, and more DPS means more agro.
Special Bears and their Attack Speeds : Ursol'lok 1.4 AS (Conflict), Mongress 1.3 AS(Unconfirmed), Old Grizzlegut 1.3 AS(Conflict).
Boar
Classification = Defensive
(Official Classification = Defensive)
High Health (1.04), High Armor (1.09), Low Damage (0.90), Fast Attack speed (1.2 - Conflict).
Level 60 optimized example spec : Stamina 8 / HP = 3494 / Armor 8 / Armor = 4907 / Bite 8 / Charge 6
Stats : The most balanced of the Heavy Tanks in tank stats, they are only slightly below a Bear stat wise.
Abilites : They have Charge which is not a tank specific ability, but a nice utility. They have Dash, but I feel that is redundant if you have Charge already. Their DPS ability is Bite, which is fine. So when training your Boar you could choose to not train Dash and put the saved points in Great Stamina ( more Health ) for example.
Special Boars and their Attack Speeds : Grunter 1.2 AS (Conflict).
Turtle
Classification = Defensive
(Official Classification = Defensive)
Medium Health (1.00), Very High Armor (1.13), Low Damage (0.90), Fast Attack speed (1.4 - Unconfirmed).
Level 60 optimized example spec : Stamina 10 / HP = 3452 / Armor 6 / Armor = 4939 / Bite 8 / Shell Shield 1
Stats : They have only Medium Health but Very High Armor to make up for it. Stat wise they are slightly weaker than a Boar and a little weaker than a Bear.
Abilites : Even tho they have slightly weaker stats than the other Heavy Tanks, they are the only ones with a pure tank ability : Shell Shield. They also have Bite for some DPS. Because they only need to put points in 2 active abilites and Shell Shield costs less than the other abilities, they have more points to put in Great Stamina compared to the other Heavy Tanks and make up for some of their Health deficit.
Special Turtles and their Attack Speeds : Cranky Benj 1.4 AS (Unconfirmed).
Heavy Tank conclusion :
I believe all the Heavy tanks have their Pro's and Con's and they all have a place where they can shine. Ultimately you will choose based on your personal play style, look and feel and which Attack speed version you can find.
Medium-Heavy Tanks
Scorpid
Classification = Defensive
(Official Classification = Defensive)
Medium Health (1.00), High Armor (1.10), Medium-Low Damage (0.94), Medium Attack speed (1.6 - Confirmed)
Level 60 optimized example spec : Stamina 9 / HP = 3372 / Armor 7 / Armor = 4945 / Bite 8 / Charge 6
Stats : They sacrifice a little bit of tanking stats for slightly more DPS compared to the Heavy Tanks.
Abilites : They have 2 DPS abilities (Poison and Claw) in addition to their higher base DPS, more DPS means more Agro.
Special Scorpid and their Attack Speeds : Death Flayer 1.6 AS (Confirmed).
Crab
Classification = Defensive
(Official Classification = Defensive)
Low Health (0.96), Very High Armor (1.13), Medium-Low Damage (0.95), Slow Attack speed (2.0 - Confirmed)
Level 60 optimized example spec : Stamina 9 / HP = 3249 / Armor 8 / Armor = 5184 / Claw 8
Stats : They sacrifice a little bit of tanking stats for slightly more DPS compared to the Heavy Tanks. Their lower Health makes them a little bit weaker compared to the other Medium-Heavy and Heavy tanks.
Abilities : They only have 1 DPS ability Claw, so not much choice. On the other hand, this frees up some points to invest in Great Stamina.
Special Crabs and their Attack Speeds : Unfortunatly there are no known Crabs with faster than base Attack speed.
Medium-Heavy Tanks conclusion
For the Medium-Heavy tanks, the case is more clear. If you want a tough tank and still be able to do some DPS, the Scorpid is the clear winner. They have more options in DPS, they have a faster Attack Speed version and overall better tank stats than the Crab. The only reason to choose a Crab over a Scorpid is for Roleplaying purposes and Look and Feel depending on your preference.
Medium Tanks
Gorilla
Classification = Balanced
(Official Classification = Defensive)
High Health (1.04), Low Armor (1.00), Medium Damage (1.02), Fast Attack speed (1.3 - Unconfirmed).
Level 60 optimized example spec : Stamina 7 / HP = 3384 / Armor 9 / Armor = 4824 / Bite 8 / Thunderstomp 3
Stats : They aren’t Heavy or even Medium-Heavy tanks, even though officially they are classified as "Defensive" they are in practice Balanced pets like Wolves. They do have higher Health compared to most of the other tanks. They also have the highest base DPS of all the Tanks.
Abilities : For abilities they have Thunderstomp (AoE damage), which is pretty unique for pets and can be used for AoE tanking. They have Bite for single target DPS. As a tank they will only have to put points in 2 active abilities, saving some points for more Armor.
Special Gorilla's and their Attack Speeds : Kurmokk 1.3 AS (Unconfirmed).
Tallstrider
Classification = Balanced
(Official Classification = Defensive)
High Health (1.05), Low Armor (1.00), Medium Damage (1.00), Fast Attack speed(1.3 - Confirmed).
Level 60 optimized example spec : Stamina 7 / HP = 3414 / Armor 9 / Armor = 4824 / Bite 8 / Dash 3
Stats : Same as Gorilla’s they aren’t Heavy nor Medium-Heavy tanks. They have more Health than most of the other tanks though and overall they have slightly better tank stats but lower damage than the Gorilla.
Abilites : For abilites they have Dash which gives some nice utility, and Bite for some DPS, same as Gorilla's they only need to put points in 2 active abilities, leaving some points to put in Armor.
Special Tallstrider and their Attack Speeds : Ornery Plainstrider 1.3 AS (Confirmed).
Medium Tank conclusion
Both the Tallstrider and the Gorilla have their perks, the Tallstrider has slightly more Health and a confirmed Fast Attack Speed, the Gorilla has the unique AoE damage ability Thunderstomp that gives them an edge for Tanking multiple mobs and they have slightly higher base DPS, which none of the other Medium and Medium-Light tanks have.
Medium-Light Tanks
Wolf
Classification = Balanced
(Official Classification = Balanced)
Medium Health (1.00), Medium Armor (1.05), Medium Damage (1.00), Fast Attack speed (1.2 - Confirmed)
Level 60 optimized example spec : Stamina 7 / HP = 3262 / Armor 8 / Armor = 4879 / Bite 8 / Furious Howl 4 / Dash 3
Stats : The stereotype Balanced pet with Medium Health and Medium Armor.
Abilites : They have Dash to close the distance, Bite for DPS and last but not least Furious Howl for improved DPS of your party. None of these abilities makes your pet tank much better, but it's nice to have some utility.
Special Wolves and their Attack Speeds : Slavering Worg AS 1.2, Deathmaw AS 1.2, Ghostpaw Alpha AS 1.3, Mist Howler AS 1.3, Enraged Stanley AS 1.3, Prairie Wolf Alpha AS 1.4, there are more of them, but these are the fastest ones.
Carrion Birds
Classification = Balanced
(Official Classification = Balanced)
Medium Health (1.00), Medium Armor (1.05), Medium Damage (1.00), Fast Attack speed (1.2 - Confirmed )
Level 60 optimized example spec : Stamina 7 / HP = 3262 / Armor 8 / Armor = 4879 / Claw 8 / Screech 4 / Dive 3
Stats : The stereotype Balanced pet with Medium Health and Medium Armor.
Abilities : They have a ton of abilities but unfortunately you can’t choose them all. My choices would be Screech and Dive, and then choose between Bite or Claw. Obviously Growl is imperative but costs no points.
Utility wise they will end up about the same as Wolves with 4 abilites, you just have more choice initially.
Special Carrion Birds and their Attack Speeds : Spiteflayer 1.2 AS.
Hyena
Classification = Balanced
(Official Classification = Balanced)
Medium Health (1.00), Medium Armor (1.05) and Medium Damage (1.00), Fast Attack speed (1.3 - Confirmed)
Level 60 optimized example spec : Stamina 8 / HP = 3312 / Armor 8 / Armor = 4879 / Bite 8 / Dash 3
Stats : The stereotype Balanced pet with Medium Health and Medium Armor.
Abilities : They have less choice than Wolves or Carrion Birds. However since they will only have to spent points on Dash and Bite, you can use the points saved to increase Stamina and Armor and make it a thougher tank.
Special Hyena's and their Attack Speeds : Tamed Hyena AS 1.2 (Unconfirmed), Ravage AS 1.3, Murderous Blisterpaw AS 1.3 (Unconfirmed), Giggler AS 1.4 (Unconfirmed), Galak Packhound AS 1.5, Scarlet Tracking Hound 1.5 AS, Scarlet Hound 1.5 AS (Unconfirmed).
Crocolisk
Classification = Balanced
(Official Classification = Defensive)
Low Health (0.95), High Armor (1.10) and Medium Damage (1.00), Slow Attack speed (2.0 - Confirmed)
Level 60 optimized example spec : Stamina 9 / HP = 3219 / Armor 8 / Armor = 5070 / Bite 8
Stats : With the lowest Health of all the Tanks and not enough Armor to make up for it the Crocolisk is the weakest of the Tanks when it comes to stats, even though they are officially classified as “Defensive” pets.
Abilites : They have only the most basic of abilities, Bite for DPS, this does leaves many points to spend for improving Stamina.
Special Crocolisks and their Attack Speeds : None.
Medium-Light Tanks Conclusion
From all the Medium-Light Tanks I would say only the Crocolisk is clearly subpar. Sure you can put the points you save from having only 1 active ability into Stamina and then he is on the same level in stats, but that just means you tank the same but have no utility while all the other Medium-Light tanks can have the same stats with more Utility. While the Hyena doesn't have that many choices in abilities, if you like his look and feel, he can still compete for your pet slot by giving him more Stamina and/or Armor. Overall Wolves and Carrion Birds have an advantage with their well rounded stats as a Medium-Light tank while at the same bringing plenty of utility Abilities to the table. So for Medium-Light tanks Wolves and Carrion Birds are the top choices.
Changelog :
Version 1 : Started with a Top down approach which implied that the Top Heavy Tanks were always better than the Medium Tanks.
Version 2 : Changed the Narrative and made it more about the Pro's and Con's of each Tank, which means that a Medium Tank could be better for some playstyles than Heavy Tanks for example. Made it clear that Classification of the Tanks is purely based on Stats only and not abilities, however there are some Tanks that are simply worse than others.
Version 3 : Full rework of the guide, made a structure of Stats, Abilities and Special. Added a conclusion for each Tank classification (Heavy, Medium-Heavy, Medium, Medium-Light). Added General Concepts. Added Attack Speed for all the pets.
Version 4 : Added Optimized example specs for all the pets.
Version 5 : Revised my conclusions.
Version 6 : Confirmed Attack Speeds.
Version 7 : Made notes and Changed Attack Speeds that are not confirmed because classic-pets.com and vanillawowdb.com have several faulty entries and I can not be sure if the rest is reliable.
Version 8 : Updated Attack Speeds and added some info on the normalization of pets in Classic, reflecting the mid Vanilla era.
Version 9 : Corrected the benefits of Faster Attack Speed.
Version 10 : Corrected the Attack Speed of Crocolisks ( to 2.0 ) and changed the wording of the Mefium-Light tanks Conclusions so that it is clear Wolves and Carrion Birds are the best choices there.
