Fun fact :
-"aligatoro" (or "alligator") is from latin "lacurtus", which is a lizard.
-"krokodilo" (or "crocodile") is from ancient greek "κροκόδειλος" (krokódeilos),.wich is a lizard.
Do malsimilaj and malsamaj not mean the same thing?
No, not quite.
"Ili estas malsamaj" would say that the two are not the same; "Ili estas malsimilaj" is even stronger and says that they are not even similar.
I chose one "malsimilaj" and got it wrong because I didn't choose both.
Inasmuch as alligators do speak esperanto?