#antierrorsans

So, in a nutshell: unlike the regular Error, Anti-Error Catnap originated from EFT—he’s not just some half-assed crossover idea. He is

Theo, not a cartoon character. His "Error" symbols appear only on the parts of him that are glitching. He’s creepy, not cute. He’s also kind, not evil. While the regular one goes around thrashing everyone like a hysterical mess, Anti-Error just sits there farming aura. Anti walks on all fours and is more playful—unlike the usual grumpy cat who walks on two legs.

There’s always a "game launch error" symbol behind Anti-Error; he can use it to reincarnate and be reborn, or as a portal. He didn't change colors, either; he just got darker. Also, he’s a bit like Prunsel.