Salen is from a small fishing village called Jonigar in the far north.  When Jonigar was under threat by nasty pirated known as the Hell Sharks, his people gave Salen as a tribute to the raiders.

 

Though he managed to escape the Hell Sharks, Salen was captured by slavers and sold to Boss Coyote who later gifted Salen to Voonder.

 

Image from V is for Voonder.

Voonder decides to free Salen.