On the first boss located in Sunnywood (takes place at the Sunnybowl) begin by rushing the stage using your jet pack.

You don't need to worry about his minions but it makes this strategy more easy to complete.

Warning, this cheat is next to impossible to do without your Zap o Matic damage and duration as upgraded as you can before this fight.

Attack the creatures balls, no really, that's its weak point as Pox will tell you.

Drain him until he sends you flying to the back, he will summon more minions.

This time it is 100% guaranteed that if you fight his minions you will die unless you are the most epic person in history, so run as close as possible then freeze time, whip out your Ion detonator and hit him with all three charges, then zap him for a second or two and he will die.