Sellikro was the searat Captain of the Hellfang, under the command of the wolverine Skarvandra the Brutal. His job was to sail the Seas in search of treasure and slaves for the wolverine warlady, and he absolutely hated it- Because Vargo and other white-furred soldiers were ordered to accompany him and his crew wherever they may go.
At some point his crew crossed paths with Flinky and his gang, who wanted to join them, but after hearing Halfchop speak, apparently, they refused them the job, instead chaining all of them up as slaves.
Sellikro's shown to be afraid of Salamandastron and its badger rulers, seeing it as a cursed, deadly place, for good reason, and protests when Vargo instructs him to kidnap the squirrel Fenna and the badger Melesme. He and Vargo succeed, but barely escape with their lives.
Knowing that because of his rather late return that he'd be punished and already long tired of Skarvandra, he devises a plan to sail off with his first mate, the ferret Deadlug, and no longer have to bother with the wolverine.