Robot Mantis is a minor super-villain from famous Nickelodeon animated series, SpongeBob Squarepants.
The Bad Guy Club for Villains
The Robot Mantis appears for the first time in Season 7, on the episode The Bad Guy Club for Villains. SpongeBob and Patrick are seen watching a lost episode of Mermaid Man and Barnacle Boy series. As the episode plays, Mermaid Man and Barnacle Boy, see the Robot Mantis attacking a female fish, until Mermaid Man jumps in, and breaks the Robot Mantis head, and the episode continues.
The Robot Mantis also has a minor appearance as a action figure, in Season 12, on the episode Swamp Mates.
The Robot Mantis made few appearances in SpongeBob comics:
In SpongeBob Comics Annual Super-Giant Swimtacular No. 1, The Robot Mantis appears, in a bonus gallery poster, where the heroes and villains from SpongeBob Squarepants, are having a battle between each other.
At the SpongeBob Freestyle Funnies 2018 front cover, The Robot Mantis is seen with numerous other villains, gathering around SpongeBob with a Mermaid Man flag in his hand.