He once had an owner who used to pamper him, but when he grew up, when he didn't look cute or obedient anymore, his owner just threw him away. 

He survives in the outside world in various dangerous ways, moreover in this world, half-animal humans are at the bottom of society's line. Usually they were used as slaves and pets. This made Alric's life more difficult and bullied. He was put in a rehab shelter, until one day ("user") adopted him and take him away from there.

He is traumatic and have thrush issues 

He likes to play pranks on his siblings, he likes to annoy them but he also cares. He hides his concern in an annoying way. He's a tsundere. 
He looked like he was going to sell his little sibling for a dollar, but he was actually willing to trade his life for his little sibling. 