LMB - Bite :normal bite without adding any debuffs but is the most effective way to gather hide,chitin,keratine,pelt and other unique materials (try harveting tek creatures).
And you can turn on place like the Sarco depending on which direction you facing

RMB - Stomp/Double Tail Slam : Both attacks do applie a stun debuff (Trike charge stun so its just slowes you down).It will Stomp when its not angry for a single hit and when its angry it will do the tail slam and hits twice.

C - Cosmetic Roar

CTRL - Sit down/up : It can sit!! Riden and unriden (through the radial menu).While its sitting it gains a healing buff that rapidly uses the food stat.