The octopi appear in "Octopus Castle". Octopi attack by using their tentacles to pound or ensare opponents. Not only can they shoot ink to block their foe's vision, they also have a special power which allows them to suck the colour out of objects. In "Octopus Castle", Octopus King, under the order of the Zebra Brothers, had his soldiers suck out all the colour in Big Green. First Squad then set out to retrieve them, only to fall right in to an octopi ambush. Mighty Ray lost his colour too, but they managed to defeat the octopi and get to Octupus Castle. Octupus King then challenges them to a bamboo-jumping contest where they must jump without getting clipped. Mighty Ray gets knocked out, but when the others hold on the Zebras have them blow their ink to obstruct their vision. However, this ends up making Jumpy Ghostface's swirling eyes stand out and when the octopi and Zebras look into them, they get caught in his fantasy. There, they get attacked by a Tyrannosaurus only to be saved by Jumpy Ghostface. Out gratitude, the octopi return the colours and join Big Green.
Octopi have big round heads, white eyes with small black pupils, a short tube like mouth, and 8 tentacles. They come in sunny yellow, mauve and salmon pink colours.
- They are called Octopi when the correct term for plural (more than one) would be "Octopodes".
- However, throughout "Octopus Castle", the plural is mistakenly used as "Octopuses"