Baby SpongyBaby Spongy is a character recommended by DragonBallNC in "The Reveal". It is a version of Spongy with a pink pacifier and a brown diaper.
Blue SpongyBlue Spongy is a recommended character who was recommended by simondomino in "Bowling, Now With Explosions!" It is a blue version of Spongy who had already appeared in the April Fools puppet show at the beginning of the episode. He is also an actual, real-life sponge.
Blue Spongy is the only non-contestant character to have a speaking role.
Evil SpongyEvil Spongy first appeared in "Gardening Hero", gasping. He was recommended by ILVGwebmaster, MechaXenoxine55, and coolmatt1019.
Eviler SpongyEviler Spongy first appeared in "Today's Very Special Episode". In this case, he is an eviler clone of Spongy. He was recommended by Billy S.
Giant Cyan SpongyGiant Cyan Spongy is a giant, cyan version of Spongy. It was recommended in "The Glistening", however, their actual appearance was in "Hurtful!". It was recommended by UtopianJenna. They appear to be legless, or their legs were covered by the sign in front of them.
Green SpongyGreen Spongy is a green-colored variation of Spongy that was recommended by Crackerz. It appeared in "Return of the Rocket Ship" in the third batch of recommended characters, as A Better Name Than That was digging.
Plasma Spongy was recommended by alexlion05. He is similar to Spongy, except being a glowing green due to being composed of plasma. He appeared in "The Glistening" and voted for Ice Cube to be eliminated.