Tentacle monster

A tentacle monster appears in the 1987 TV series episode Splinter No More. After Shredder accidentally opening the portal to the wrong place, the monster arrives to Earth.

The monster, which has one eye, appears in the abandoned New York City Subway station. The Ninja Turtles, Splinter and April O'Neil team up with Shredder, Bebop and Rocksteady to fight the monster. Together, they trick the monster to use its tentacles to break the pillars, causing the ceiling to fall apart, killing the monster.