knuckles
The name of a baby ecina is a puggle. I now it souds funny but this is the truth and im not trying to trick you.
Canon wise, you could say that Rogue and Knuckles have a "thing". You could also say that he likes Tikal, another Enchinda in the STH univserse. But nothing was and probably never will be announced that Knuckles has a "crush" on any character.