* Rick Sanchez from Rick and Morty? He doesn't seem to have a favourite animal explicitly, but he does show a fondness for Snuffles (the dog) and Morty's pet, a rat.
* Rick Grimes from The Walking Dead? He might have a soft spot for dogs, as he was shown to be attached to his dog, Hershel.
Let me know who you're talking about, and I can provide a more accurate answer!