Here are a few rare monster ideas i came up with for different monster families. If you want to, expand the list as well!
1- Basilisk
This one is simply a kleptolisk with a stranger hat on (*ba duuum tss*). it cant steal things from a players belt, and does tongue attacks ; chance of spawning in the place of any chromalisk. Drops: besides regular ones, chance of dropping any stranger hat (x1)
2- Insanity Wolver
A grey wolver with a black back, chance to spawn in the place of any wolver. It teleports around crazily, and swiftly too. Rarely bites, but will if given range. When killed, it may drop an ''Insanity wolver mask'' for you to wear on your face. (yeah, theres a joke here too ¬¬)
Well, thats the first batch, might come up with more later. anyone else?
"Basil"-isk, we see what you did there. Does it or does it not steal things? Your post says it does not, yet it still attacks with its tongue. No to dropping Stranger hats, that would cut a few fingers off the economy.
See T3 Wolvers, without your silly mask. If you want the mask make it an independent concept with stats and art.
We already know Tortrodone is coming back eventually, so no one bother mentioning it here.
What would I like to see? Snakes, bears, killer plants, living statues (a new variant of Trojan), cavaliers, spiders, and rats.
Snakes would be able to strangle knights similar to zombie jumps but with less warning time for a "boa" mechanic while "venom" mechanic snakes inflict various statuses along with damage with their bite.
Bears would essentially be Tortrodone but only found in sidepaths where treasure is often found in dead ends, guarding it from wandering knights.
Killer plants, somewhat self explanatory; they are plants and they want to kill you.
Living statues, I remember something from Zelda relating to this; you turn around and it starts to walk, when you face it again it stops.
Cavaliers, jousting, being kicked in the head by a horse; good times.
I made a post about spiders somewhere, if I find it I will link it here.
Rats with an AI imitating pirahna; see these pests for a general idea.
These are just basic ideas with minimal detail. If anyone wants me to expand any of these I can, for a price. No, I kid, I can do it for free; that does not mean lobbyists are not welcome. No, I kid again, just ask if you want to read more about these. If I have time I will edit in more details.