The animal crossing wiki has a blurb in the trivia section saying he does this if you catch an octopus near him (doesn't specify which game but i'm assuming City folk).
animalcrossing.fandom.com
I feel like that has been there on the wiki for years and yet i've never once seen proof of it actually existing in any game. Maybe i'm just not looking hard enough but I can't find anything. I don't care what it takes I just really want to see if it's true or not.
Octavian
“But first and foremost, I'm an octopus!” ― Octavian, Wild World Octavian (おくたろう, Okutarō?, Octarō) is a cranky octopus villager from the Animal Crossing series, first appearing in Animal Forest. His name is derived from Gaius Octavius, the first emperor of ancient Rome, who later adopted the...
animalcrossing.fandom.com
