The skull of the grifolaroo resembles that of the old Slayer icon, which is depicted as an animal skull.
The description seems to hint that the name "grifolaroo" is a reference to kangaroos.
Occasionally while fighting the grifolaroo, it will say "Hup!". It is the only monster along with the grifolapine to have a dialogue in Polypore Dungeon rather than the "Ssss!" and "Krrr!".
There is a glitch where if the grifolaroo says "Hup!" and soon gets its cover back and you click on your neem oil, you spray the neem oil on another monster instead rather than the monster you are targeting. This also affects attacking too.
If a player manages to deal a killing blow on a grifolaroo when it says "Hup!" the death animation will not be seen. This also is similar to landing a killing blow on an abyssal demon during the teleportation phase.
It is possible for a grifolaroo to jump into an inaccessible area to players, making it impossible to collect your drops unless players bring runes for Telegrab.
The examine text resembles that of a zygomite: "A bouncy fungus" versus "a bouncy creature covered in...fungus".