|Nerd Boss Fight|
|Item||The Spud Gun is available in Jimmy's room|
|Trophy||Planet Mobile room trophy|
Earnest has transformed the inside of the Observatory into a stronghold. He stands up on an inaccessible catwalk. Jimmy at first tries to reason with Earnest, but Earnest won't hear it. He says he's tired of "friends" like Jimmy who pick on them constantly. Ignoring Jimmy's response, he opens fire with an automatic potato gun much like the one outside.
This boss fight is split into 3 parts. Earnest is up on the catwalk, the railings of which prevent Jimmy from shooting at him directly. Down on the floor where Jimmy is, there are pillars he can duck behind to avoid Earnest's attacks.
The first part has Earnest firing at Jimmy from a rapid-fire spud gun. Jimmy has to shoot the machines that hold the catwalk up. Once they've been damaged, part of the catwalk drops away.
Earnest then begins throwing firecrackers with a delayed explosion. Again, Jimmy has to shoot at machines holding up the catwalk to stop him.
The final part has Earnest take a hand-held Spud Gun and fire at Jimmy. Jimmy shoots at more machines, and this time Earnest comes crashing down with the catwalk.
Earnest cowers, sure that Jimmy's going to beat him up. He hands over the spud gun. Jimmy helps Earnest to his feet and again asks for his help. Earnest agrees to help him, although he does make it clear he's only doing so because he has no other choice.
When the mission ends, it will always be 7:00 p.m.
- The boss fight against Earnest is the only boss fight in the game without a unique soundtrack, instead using the generic "Vendetta Nerd" theme.
- The Spud Cannon in the PS2 and Xbox version of the game both have their own design.
- Like all other boss fights, if Jimmy is knocked out, it continues from the fight rather than starting the mission over.
- After this mission, despite the Nerds' 50% respect for Jimmy, the Nerds will treat Jimmy as if Jimmy has 100% respect with Nerds. For example, you can still hire their boys as your back-up after this mission.