A hero is anyone or thing (animal) that does something that receives admiration from the public or a group of people. An example of an animal hero can be the dogs used in wars that protect their master under all situations. They even stay with their master to keep them company or, in some reported cases, even going to bring back a medic.
animals can also be hero's, real or fictional.
That is what heros-and-villains fandom defines hero since it made an article for the t rex from jurassic world on its site. here is its link:
A hero and villain need a human like level of sapience to count here. I don't even know what elephant you are talking about and don't care what another website defines especially when it has far lower standards.