Fun fact about the etymology of "alligator:" When the Spanish first landed in what is now Florida, they found alligators and simply called them "el lagarto," which literally translates to "the lizard." While there were many reptiles in the swamps and bayous, only one was enough of a problem to be called "THE lizard," and after several mistranslationsbeing borrowed into other languages, "el lagarto" morphed into "alligator"
Good to know! I took years of Spanish classes and my kids are in a Spanish immersion school in California, but I've only ever heard lagarto for smaller lizards and cocodrilo for anything resembling crocodilians
All of this is correct, except that it's not a "mistranslation", it's a borrowing. Boundaries between words and morphemes are commonly lost in borrowing, and borrowed sounds commonly undergo adaptation as well.