On Friday the 13th, kittens, housecats, and large cats are referred to as “black kitten/housecat/large cat”.

In variants with shallow water, pet cats will avoid it similar to how they avoid squares containing cursed items.

Rat corpses are treated as “treats” (highly desired food) for the purpose of feeding them to cats.

Pet cats lose 2 tameness when the player wakes them up. However, opening a tin wakes all nearby felines, and this will not cause cats to lose tameness when woken.

If you displace a tame or peaceful cat onto watery terrain such as a sink or fountain (or shallow water, if implemented) it automatically attacks you, though it doesn’t actually go hostile; it’s a one-off reaction to getting wet.

Add a TDTTOE message about swinging your dead cat if you start hitting things with a wielded cat corpse. Also have a separate message “There isn’t enough room to swing your dead cat” if there are 4 or more walls adjacent to you.

Dogs are buffed to be better fighting than cats as a starting pet, but lose their ability to curse detect.