A memorable guardian creature I used several sessions ago.
NECROTIC BEHEMOTH Solitary, Huge, Construct, Undead, Terrifying
Bite and Rend (1D10+2 damage) 18HP 1Armor
A bulbous, balloon-like beast approximately 40 feet in diameter and 40 feet high, covered with the stitched-together skins of human corpses whose arms and legs flail like cilia enabling it to walk and strike out at its prey. It leaks black ichor from the orifices of the skins stitched together to make it’s surface.
Instinct: To crush them.
Heal by absorbing a corpse.
Grapple w/ multiple arms and then bite & rend
Smash them flat
Vomit tar to slow them down
Drench with tar to instill fear (Q: What is your greatest fear?)
It stood guard over a lost ruins, vine covered and deep in the jungle containing: 1. gold coins stamped with a skull 2. vials of ectoplasm 3. hungry mirrors which confront the party with your their murderous dopplegangers 4. a ruby ring that returns 1 point of health for every pint of blood the wearer drinks 5. some pre- triggered traps 6. a closed gate to the shadow plane 7. an empty altar
8. chittering shadows 9. an empty phylactery, a tome, and supplies necessary to become a lich 10. foul magics in a forgotten tongue