I'm guessing you're referring to good movers so not the basic hobbies or donkeys...
and ones that you can obtain currently in game (so the archon, snow slime, tron bike, faithful dragon, etc. from past events are out)
I'll probably miss some but the 6 I know of are:
1. The king crab mount from lucky house (blue 1 capsules-low rate).
2. The car mount from getting a max bet jackpot on the slots in lucky house.
3. The Kentauros of Darkness mount from the level 108 "The gradual unfolding of the truth" quest.
4. The iron horse mount from the level 90 "Final rest 1" quest.
5&6. The 2 Perm mounts from the attendance NPC in roumen.