Met them all.

Penelope AUs - relations 2

-and here they go ((plus shreds of ✨lore✨ under lol)):

^ "An oversized mini-sentry."

[After being left out to be looked after by the skeleton brothers, its habits became similar to both of the skeletons. Around Sans - naps, pleading for food (hotdogs wo ketchup as treat), messing around with the royal guard (except for Undyne), stalking and watching, keeping an eye on Papyrus and carrying the skeleton around from time. Around Papyrus - playtime (zoomies included), occasional fur brushing, puzzle testing, improving the dog house (Paps believes if he can fit through door, it can too...eventually), finding Sans and chasing Toby the annoying dog.]
[Sometimes gets leftover snacks from Grillby left out by the back door.]

^ "We are keeping it."

[Similar to Undertale, but swapped habits observed from the two brothers. Biggest difference would be its hunting practicing as well as Sans' royal guard training. Being a feline (sabertooth), it sneaks before pouncing at Sans (always ensuring to avoid any harm to him otherwise doesn't get treats from Papyrus later), they mess around a little and eventually the sabertooth carries the smaller skeleton away as its trophy. The only way to avoid it is by distracting it with a small bone in orange attack (or any bright and quickly moving object. Paps lets it sneak into the house on occasion, at least while Sans's away. Muffet's been requested not to feed it sweets, but on occasion it finds unsweetened and undecorated pastry outside the back door.]