Daxter spends much of the opening cutscene of Jak II cowering in fear and shrieking in a womanly manner, until the opportunity to run away presents itself. At which point, he abandons his “best friend” to two years of torture and experimentation at the hands of Baron Praxis.
Above: Proof that Daxter is a worthless sidekick (4:25)
It’s later revealed in Daxter’s PSP game that he was looking for a way to free Jak, but couldn’t find him so gave up and took to bragging about his courageous struggles in the local bar. This promptly landed him a job as an exterminator, through which he accidentally discovers where Jak is being held. To Daxter’s credit, he at least feels guilty enough to stage a rescue.