First of all, this game is awesome!
With that being said... I would like to suggest some animals that could be cool to have.
jaguar (this one could have a name or an outfit as a reference to "Tezcatlipoca" a god from Mexican prehispanic cultures)
bison
capybara
bald eagle
toucan
capuchin monkey
axolotl
& raccoons (I think they are not endemic to the American continent)