Born and raised on Kashyyk, Khroatrrrum was trained in combat since the day he learned how to walk.
He always cherished his family bonds and was a loyal friend to anyone he deemed a decent person.
When the Clone Wars began, he ferociusly defended his planet from day one, he shared the trenches with his childhood firends and clones alike. Every day he watched his friends die one by one. He fought until the very end, when Order 66 came. On that day his entire unit was killed and he barely escaped with his life.
Having nothing left for him on Kashyyk, he left the planet with nothing but his weapon and thirst for revenge.
Since then, he worked and odd job here and there, either in security or as a deckhand on starships. He doesn't give his trust easily to anyone after Kashyyk and he generally won't befriend someone whom he doesn't expect to be around for long.
To those he does befriend, he'll remain loyal and will selflessly help them ayntime.
While he may seem cold and cynical to those he don't know him, his friends know that his true presonalty shines when he is alone with his group.

He hates the Empire with every hair on his body.
Growth; Jedi Order

Loud, hairy, tall, strong and sometimes somewhat smelly Wookie.