My additions:
Cnidaria. Nerf it. Give an individual tame a cooldown from stuns. Make the jellies not follow you and have better more realistic animations/physics, potentially just ragdoll while alive.
Beelzebufo
Aimed jump, much reduced fall damage, VISUAL REWORK DESPERATELY NEEDED, better "aiming" mechanics- currently is only able to hit things pretty much on its level, often even struggling with meganeura. It should be able to lift and turn its head somewhat more.
Manta
I think they need to be easier to tame. If you trap them, they aggro your structures, if you let them roam they end up on the other side of the ocean. Visual rework would be nice and an armour piercing attack quality would give them a bit of extra use imo
Megalania
Currently outclassed drastically, when it was new its abilities were unique. I think they need better damage and health and the spawns properly added to aberration. Currently barely worth taming with the torpor drain and lack of demand for their abilities.
Titanoboa
Needs to actually be worth taming now that their eggs are useless. Eggs should be of special quality, they should be able to do increased damage to small (5x) and medium creatures (2x), harvesting them on the death blow (swallowing them whole). Damage and health buffs.
Anky
Natural incoming damage reduction, auto swing like a doed
Compy
Visual upgrade needed, speed increase and maybe behavioural change like running around the victim rather than biting from one position.
Enforcer
Small incoming damage reduction from all sources, larger reduction from corrupted
DUNKLY
Weight reduction by 50% for metal, crystal, obsidian and stone. Should be damaged by jellies but not stunned. Speed increase by some amount, not to make them super speedy but to make them at least worth using as an alternative to the argy/quetz/crab method. More resource nodes should be added to oceans of all maps with them.
Moth
Mortar and pestle saddle, allow weapon use. Silk production and visual rework would be nice.
Bee
Settings on hives to allow a primitive turret
They should also be updated for yellow and black to be possible wild colour rolls!!!!!
Giga
Needs visual tlc
Ravager
Wild and tamed alphas should have a bleed but a less damaging one. They should also reduce the weight of ingots and pelt/wool, to go along with their affinity to mutton and lamb.
Ptera, tape
Visual tlc, ability to pluck fish from the water and harvest them, greater affinity to fish for healing and taming
Seeker, make em tamable. Featherlight seeker armies ftw ?
Terror bird
Visual tlc, better damage (another case of being more effort to tame than their use in practice)
Dinos that are most in need of a visual tlc, imo: Carno, dimetrodon, dimorph, beelzebufo, vulture, the pterosaurs, the plesiosaurs, phiomia, mesopithecus (sound too, grown-ass man voice coming out of a tiny monkey is more than a little unnerving), megaloceros, mammoth, carbonemys and compy.
FOR ALL WATER CREATURES: I would like to see their oxygen stat drain when out of water and them have a health drain rather than the insta death we currently get. Having vacuum structures usable and non deadly on the plesiosaur pals would be nice too.
sorry for the novel lol