Hyenas:
Currently, Hyenas are just wolves, but worse. They have no custom ability and identical stats. They need a special family skill, and their WotLK skill would likely be a very good fit, with some numbers tweaks.
Tendon Rip:
20 Focus
Melee range
45 second cooldown
Rips at the target's legs, dealing X damage & reducing movement speed by 50% for 5 seconds.
This can have several ranks to scale the damage done. Hyenas would have a useful niche in PvP and be a valueable kiting tool if the hunter needs a backup. Cooldown needs to be long enough to justify the power of the slow, WotLK's version is far too short.
Croclisks:
These also have no special skill and are in a very weird spot. They also have no movement skill, making them largely worse pets than most. They have high armor & moderate damage, but no useful way to catch up or hold threat. I suggest giving them Dash. Their WotLK skill is also a great candidate, and was even their ability in vanilla's development!
Bad Attitude:
10 Focus
45 second cooldown
Snap back for X to Y damage at any target that strikes the Crocolisk for the next 20 seconds.
This should also have multiple ranks to adjust for scaling damage at diferent levels. This would make Crocolisks excellent AoE farming partners I like to think. Hunters are currently very poor at farming compared to others, despite being the stereotypical farming class, largely because they only excel at farming 1 target at a time.
Bears:
Largely the same story of Crocolisks, bears also lack a movement skill and any class skill, while also having excellent tank stats (though a different, more defensive spread) and very poor threat. Slap Dash on them and a good threat skill and they would be a lot of fun!
Swipe:
25 Focus
Melee range
5 second cooldown
Swipe up to 3 nearby enemies, dealing X damage. This spell generates additional threat.
I'm not quite sure on the math for this one, but something in this vein would make them very reliable solo partners without having them need to deal extra damage, allowing them to be a tough tank! Bear druids swipe, why not real bears?
Boars:
Boars are largely great pets. Walking garbage disposals, they'll eat anything and get the job done. However, I have one gripe: Dash and Charge share a cooldown. There's no real balance reason for this-- they aren't high damage dealers, and Charge isn't a particularly short cooldown or powerful spell. Remove the shared cooldown on the two and increase the root duration of Charge to 2s. Would also recommend reducing the cooldown of Charge to 20 seconds, as boars have the LOWEST damage of all pets (tied with turtles)... let's throw them a bone.
Scorpids:
These are also in a great spot! However, they're missing Dash. Scorpions are surprisingly fast when they need to be, not like it doesn't make sense.
Turtles:
The undisputed tank pet champs. However, also missing Dash. They're super fast in short bursts, so not like it doesn't make sense. Perhaps make shell shield reduce movement speed if that's a concern.
Gorillas:
Cool and interesting pet. They do see some use. Also missing Dash though, so let's fix that one.
Crabs:
Crabs are really cool pets, but they're in a very sad spot. They also lack a movement skill, or anything useful at all. They don't deal a lot of damage, don't have a lot of health, and only have very high armor. Very strange stat distribution in terms of gameplay. Their WotLK skill is a really good candidate to make them see some use, but it also needs to be toned down.
Pin:
35 Focus
Melee range
1 minute cooldown
Pins the target down, dealing X damage and stunning the target for 1 second.
Giving hunters another CC tool is a dangerous thing, especially a stun, so it needs to not be up too often. The WotLK version is a great starting point, but I feel like these tweaks make it less awkward of a skill.
Spiders:
Spiders are high damage pets, but have no family skill or movement skill. We have enough PvE-oriented damage dealers, why not give them their WotLK skill and slap Dash on them? This skill is largely fine as-is, but should be slightly toned down.
Web:
35 Focus
20yd range
45 second cooldown
Sprays sticky webs at the target, rooting them in place for 4 seconds.
Not gonna lie, having an excuse to see more potential Duskskitterers charging at lightning speed in PvP sounds great. Dragunovi pls.
Tallstriders:
The last of the original pets to not have anything useful at all. This one is a shame, as the Hawkstriders in the Thalassian Highlands are lovely pets, but see virtually no use. They're known to have very thick skulls, so let's work with that.
Skull Bash:
40 Focus
Melee range
30 second cooldown
Headbutts the target, dealing X damage and befuddling them, reducing attack and casting speed by 20% for 6 seconds. Does not stack with similar effects.
Why not have fun with this one? Fits in line with the family's themes and (hopefully) isn't too strong. Tallstriders aren't strong damage dealers, so giving them a support skill seemed like the next best thing. Though, putting this on a 1.3 attackspeed Tallstrider (Hello, Ornery Plainstrider!) might be pretty nasty in PvP!
Raptors:
These guys are in a really good spot, but don't have a family skill! We can't add consistent damage to them though, or cats would pale in comparison. We also still have enough PvE-oriented damage dealer pets, so let's put this one in-line with their excellent hunting abilities in lore for PvP!
Leap:
35 Focus
8-25yd range
30 second cooldown
Leaps at the target and hooks in with claws, dealing X damage & rooting them in place for 1 second.
Let's let boars hold the title for best takedown and have them have a longer root effect and more engage skill damage, but do less overall damage & have raptors fit into a similar niche, but with more overall damage. Should not share a cooldown with Dash.
Custom Pets:
Hydras:
Diet: Meat, Fish
HP: 1.05 (High) Armor: 1.0 (Low) Damage: 1.4 (Medium)
Slowing Poison:
30 Focus
Melee range
6 second cooldown
Injects venom into the target, dealing X nature damage over 6 seconds. Slows movement speed by 20% and attack speed by 15%. Does not stack with similar effects.
I see that hydra icon in the macro selection! Let's give hydras their Warcraft 3 skill and make 'em fun! They should have Bite & Dash as secondary skills!
Thunder Lizards:
HP: 1.08 (High) Armor: 1.0 (Medium) Damage: 1.0 (Medium)
Diet: Fruit, Bread, Fungus
Chain Lightning:
40 Focus
15yd range
10 second cooldown
Breathes lightning at the target, dealing X to Y nature damage and jumps up to 5 targets, decreasing by Z% every jump.
A fun AoE pet with their canonical ability, slap Dash on them and Bite as well!
Gryphons:
Diet: Meat, Fish
HP: 0.98 (Medium) Armor: 1.0 (Low) Damage: 1.10 (High)
Updraft:
10 Focus
Rapidly flap wings, granting the master slow falling for 25s.
Gryphons having Screech as well may be interesting. If so, reducing their damage modifier to 1.07 would be recommended.
Hippogryphs:
Diet: Meat, Fish
HP: 0.98 (Medium) Armor: 1.0 (Low) Damage: 1.10 (High)
Updraft:
10 Focus
Rapidly flap wings, granting the master slow falling for 25s.
Hippogryphs having Screech as well may be interesting. If so, reducing their damage modifier to 1.07 would be recommended.
Wind Riders:
Diet: Meat, Fish
HP: 0.98 (Medium) Armor: 1.0 (Low) Damage: 1.10 (High)
Updraft:
10 Focus
Rapidly flap wings, granting the master slow falling for 25s.
Wind Riders having Scorpid Poison may be fairly fitting themeatically. If so, reducing their damage modifier to 1.07 would be recommended.
I think it's fair to have these 3 be mostly carbon copies personally, but some may disagree. Having some copies of pet families with different aesthetics is a good thing for pet diversity. Slap Dive, Bite, and Claw on these for basic skills. Alternative would be doing what retail does with the family "feathermanes", but it feels weird aesthetically.
Chimaeras:
Diet: Meat
HP: 1.0 (Medium) Armor: 1.0 (Low) Damage: 1.07 (High)
Corrosive Breath:
35 Focus
10 second cooldown
Breathes a corrosive gas on the target, reducing armor by X. Lasts 30 seconds.
Chimaeras are one of the more iconic creatures from WC3, so let's give them their canonical ability too. This should share a debuff slot with Faerie Fire, or perhaps Annihilator's debuff. Put Dive & Bite on them for basic skills.
Basilisks:
HP: 1.05 (High) Armor: 1.0 (Low) Damage: 1.0 (Medium)
Diet: Meat, Fish
Stone Gaze:
35 Focus
8yd range
1 minute cooldown
Stares at the target with a piercing gaze, stunning them for 1 second.
Don't think I didn't see you make the Gillijim's basilisks untameable with 1.17.2! And now we also have a basilisk family icon in the icon list? Let's give these guys Dash & Bite for basic attacks! Once again putting a strong CC ability on a less damaging pet.
Devilsaurs:
HP: 1.0 (Medium) Armor: 0.95 (Low) Damage: 1.07 (High)
Diet: Meat
Grievous Bite:
25 Focus
Melee range
8 second cooldown
Bite at the vitals, dealing X damage and reducing healing done to the target by 30% for 8 seconds. Does not stack with similar effects.
A mortal strike effect is cool, but let's tone it down and let arms be the #1 on that front. Slap Dash & Bite on this fella and he's looking cool. Bonus points if you add a mob with the green skin somewhere. Maybe reskin King Mosh?
Dragonhawks:
HP: 1.0 (Medium) Armor: 1.0 (Low) Damage: 1.07 (High)
Diet: Meat, Fish, Fruit
Fire Breath:
50 Focus
20yd range
Breathes fire at the target, dealing X to Y fire damage.
A carbon copy of Wind Serpents, but with fire damage and a different aesthetic. Makes the most sense, they're fairly similar in ability canonically. I suspect this might become a family 100% just for the Silvermoon Wastes content alone.
I see icons for Pterodax, Wasps, Silithids, Core Hounds, Ravagers, Stags, Worms, and Warp Stalkers. Not sure those really feel like they should be hunter pets, starts to feel less vanilla. Besides.. this is.. a lot of new families. Like, a lot. And they make the most sense, maybe barring hydras. Those were always naga-affiliated.
I could also do an entire write up of adjusting pet attack speeds, adding rare spawns for xyz unused skins, etc.. but this is LONG enough! I really like pets.

P.S. More stable slots pretty please.