Creatures Too Fluffy to Keep as Pets - Niffler
Runner Up - Creatures from the Wizarding World
When watching the movie Fantastic Beasts and Where to Find Them, everyone in the theater couldn't help but smile while the Niffler tried to get away from Newt and trying to put more gold inside its pocket in the meantime.
Actually, it's not the first time the Niffler appears in the Harry Potter series, Hagrid used Nifflers as class material for the Fourth Year Care of Magical Creatures class. Ron Weasley asked Hagrid if they could buy these Nifflers as pets, and Hagrid said his mom won't be happy because Nifflers may wreck house.
Even though, who can resist this thieving little fuzz-ball!