Ultamite (5e Creature)

Huge monstrosity, neutral evil

Armor Class 16 (natural armor)
Hit Points 123 (13d12 + 39)
Speed 40 ft.

Proficiency Bonus +3
Damage Resistances acid, cold, fire
Damage Immunities poison
Condition Immunities charmed, frightened, poisoned
Senses blindsight 60 ft., darkvision 120 ft., passive Perception 9
Languages —
Challenge 7 (2,900 XP)

An ultamite is a gigantic insectoid creature, not unlike an overgrown mite with the thrashing tail of a scorpion. Ordinarily, an ultamite's body is a sickly, almost transparent white, but as it feeds, it gradually turns a deep shade of red. Much like a parasitic mite, an ultamite subsists off of the blood of its victims, but unlike those smaller bloodsuckers, an ultamite is simply too large to cling to its prey. Instead, it sucks the fluids from their dead carcasses before leaving to digest its meal. An ultamite will attack anything smaller than itself that it perceives to be food, including other ultamites.
A single ultamite can kill an entire herd of cows or flock of sheep in one sitting and displays not even a hint of fear once it has detected prey, charging through even the most obvious danger without care for its own life. For this reason, farming communities plagued by ultamites learn to lure the creatures into hazardous terrain or the lairs of more powerful predators where they will perish.
Ultamites reproduce by laying hundreds of eggs, each easily large enough to fit a small child inside, which are then buried in loose sand or dirt and abandoned by the mother. The eggs will hatch after six weeks and the larvae will dig themselves out from the ground. Young ultamites feed almost exclusively on tree sap, though they can still digest blood and as they grow, they will gradually add more and more blood to their diet. The overwhelming majority of young ultamites never reach adulthood, as they are eaten by other predators or exterminated by those who know of the damage they can cause.