What are some imaginary animals?

There were many in Greek mythology : the centaur (half man/half horse), the harpy (women/bird), the gorgons (women/snakes), Pegasus (horse with wings), Cerberus (multi-headed dog) and so on. Mariners had stories of various sea monsters : kraken (giant squid), mermaids (half women/half fish) European folklore has the unicorn, the yeti, the dragon, the werewolf, the fairy Recent stories for children have umpteen monsters: Gollum, hobbits, Harry Potter creatures. Dr Who and Startrek invented invented a creature per week. And Hollywood invented many for monster movies and sci-fi movies (aliens).