Bishop

Bishop, formally known as Unnamed Octopus, was a character that was a replacement for Squidward in the episode, "SPONGEBOB SQUAREPANTS MONOPOLY THE BOARD GAME". Though Patrick calls him a squid (since he was a replacement for Squidward), but his appearance shows that he is a blue octopus.

His Name is revealed in the Episode "ALL HAIL THE MAGIC CONCH SHELL" When During The Chase Scene Squidward Says "OH Hi BIshop"

Appearance
Bishop has blue skin and blue tentacles.