Octagon

Octagon is an octopus monster created by Nightmare Enterprises that was sold to King Dedede, though it appeared as a tiny octopus when Dedede received it. However, for three nights, it transformed into its giant state and started eating Mayor Len Blustergas' Sheep. Dedede had no idea that his pet octopus was doing so until he filed a complaint to Customer Service about it. Octagon then took control of the king and pit him against Kirby, transforming to his true state and attacking him with mini Octagon and Kirby Inhaled them all, transforming into Fire Kirby and using the Warp Star to launch Octagon into space.

Physical Appearance
Octagon starts off as a little pink octopus minding its own business floating around in Dedede's royal fish tank. When Octagon reveals its true form, it grows in size. Octagon is so big he nearly dwarfs Dedede's castle. It has dark red skin and sunken in green eyes. In its smaller form, those eyes are black dots, unless it stares into a potential victim's eyes, in which case it is using its hypnosis with its eyes glowing green. He attacks with smaller octopi that are engulfed in a pinkish-red flame.