10 Hidden Video Game Bosses You Weren't Supposed To See
2. SpongeBot SteelPants (Third Phase) - SpongeBob SquarePants: Battle For Bikini Bottom
The final boss in SpongeBob SquarePants: Battle For Bikini Bottom is SpongeBot SteelPants, a giant robot version of SpongeBob sicced on him by the malevolent Robo-Plankton.
The boss battle has two phases, but fans ended up discovering a third unused phase in the game's code, where SpongeBot sprouts huge inflatable "muscular" arms and dons a Speedo to fight Patrick.
Though this phase can't be played to completion, many of SpongeBot's attacks and taunt animations are included in the game's files, suggesting it was relatively far into development when it was given the chop.
While the third phase was briefly featured in a trailer for the game on a bonus disc of Mario Kart: Double Dash, it's fair to say that most players quickly forgot about that fleeting glimpse.
Curiously, though, these files re-appeared in the more recent Rehydrated remake, yet sadly the cut phase wasn't restored to the battle as would've explained the files' recurring presence.