The Knight Octopus is a variant of the Dumbo Octopus, released in the 2019 Halloween Event but always available in the Halloween Tank.
The Knight Octopus is colored mainly deep brown, almost black, fading to dark maroon on its tentacles. On its head it wears a silvery blue-gray medieval knight's helmet, colored darker near the edges. Its face is revealed under a lifted visor, with four square holes arranged in a pattern on each side. Its eyes are blazing orange and red, and there is a feather on the top of its helmet fading from light red at the tip to white at the base. Its rightmost tentacle is always extended, and carries a cartoonish silver sword with a golden hilt.
To obtain the Knight Octopus, the player must own the Hungry Coffin structure and create 5 Seahorses in the Halloween Event Tank.