1. Often used in frustration, the term for that moment when the right word is somehow stuck in a way that it cannot be expressed and therefore results in either hilarity or embarrassment.
2. Refers to the eight-tentacled creature whose suction cups are replaced with painful needles similar to a cactus.
"Dammit! I keep having a cactapus!"
"A what?"
"Like a brainfart except with words."
"Never hug a cactapus. Their tentecles are PAINFUL!"