The Aculeozzo is an irregular mutant that appears in Resident Evil: Revelations. This peculiar creature appears to be a puffer fish that has been altered by the T-Abyss virus, but as viral mutations go, this one doesn't pose much of a threat. The virus has caused the fish's skin to harden and allows it to survive out of water, but all it is capable of doing is flopping about uselessly. Though lacking in offensive capability, Aculeozzo have very high defence and take a lot of firepower to kill. Knives are recommended for dispatching these creatures as using any firearms will only be a waste of ammunition.

Aculeozzo only appear in Revelations' Raid Mode and drop rare weapons when killed.