Implicating equine → mammal
Link to implication

Reason:

Equines are mammals

we would need thousands of implications to standardize this tag...

Not really, those suggestions I made cover probably 99% of mammal artwork uploaded here, as they're mostly parents for other narrower tags (ie this one covers horses, ponies, zebras, and the like).

Thus remains the question:

Is an alligator-horse-dragon-wolf hybrid still a mammal?

SirAntagonist said:
Thus remains the question:

Is an alligator-horse-dragon-wolf hybrid still a mammal?

It's not a reptile either, and it will get tagged still as reptile because of the alligator tag.