- For the Campaign, Multiplayer, and Power-Up variant, see R.A.P.S..
- "EVIL BALLS!"
- — Nero when he spots an Insanity Elemental.
Insanity Elementals, also referred to as Meatballs by Jack Vincent and Jessica Rose, are enemies that appear in the map Shadows of Evil, as well as making an appearance throughout the Nightmares mode and Dead Ops Arcade 2: Cyber's Avengening. They hunt down players, and when contact is made they explode, injuring the player, similar to the R.A.P.S. in multiplayer mode. They are made of twisted flesh with multiple glowing mouths, screaming as they roll.Like parasites they have their own special round and when the last one is killed they drop a max ammo.After the first Insanity Elemental round they appear along with Parasites after the second parasite round,
Insanity Elementals spawn into the map by falling from the sky as glowing orbs. If playing co op, they will target certain players, instead of the player near their spawn location.
They also appear prominently in the Easter Egg, during the "capture the flag" round, where they will continue to spawn until the flag has been charged and taken to the ritual site, forcing the player to protect the flag from being destroyed by them and the Shadow Man.
The Nightmares versions act basically the same as the ones in Shadows of Evil.
The Dead Ops Arcade 2: Cyber's Avengening versions act mostly the same, but now when one is damaged enough it will explode into several smaller ones.