Fifi (Boss)

General Viggo's pet human, Fifi, uses his master's Carrier to battle Tweek in Secret Island. You won't be able to continue the game unless you defeat him.

Strategy
When the battle begins, run up the nearby ramp to the very peak. As you're running around the ship, shoot the rocket launchers and exhaust pipes. Watch out for the laser - It's a One Hit Fluffer. Once that's done, start shooting the jet thruster. Finally, after the ship has fallen, glide onto the top and shoot Grenades onto the blades.

After his defeat, the way into the final battle will be opened.

Trivia

 * In the original Dreamcast game, under rare and unknown circumstances it is possible to get stuck just underneath the Carrier. When this happens, the Carrier will rise forever, eventually taking you away from the entire level.