Can you pet the Cacos? Yes.

I’m a huge fan of watching the AI fight each other, whether that’s spawning demons inDwarf Fortress’s Arena mode or carting around a suicidally incompetent security guard inHalf-Life. Enter CacoFrendo, a mod for the original Doom that lets you pet the Cacodemon until he becomes your pal and fights on your side.

You can see the pat-to-befriend method in action in this tweet by the mod’s creator:

The other category is the Half-Life security guard, theBroguemonkey, and now the Doom Cacodemon. Escort missions are clearly rubbish, but make it optional and systemic and suddenly I’ll go through enormous pain to keep an idiot NPC alive. This is the joy on whichAlice O wrote more recently in ‘What’s Better?’. (Ultimately deciding that air control was better).

If you also want to try fruitlessly to keep a Cacodemon alive and then feel sorta bad when you fail, thencheck out Frendocaco on ModDB.