Planar Bestiary
As entities of necrotic energy, ebon tulliths don't require air, food, drink, or sleep.
If a creature boasts a shadowy veneer flowing over their skin like tiny trickling threads of darkness, that veneer might be the protective embrace of an ebon tullith. If that protection is disrupted, the tullith is expelled, condensing as a darting, shadowy point in the air seeking another host, or the nearest living creature that they can use to flee back to the Elemental Chaos by creating an implosive, fleeting portal.
Because of an ebon tullith's resonance with necrotic energy, usually only undead and necromancers dare to conjure them. Long-term bonding with an elemental steeped in "negative" necrotic energy may lead to ill effects in otherwise normal creatures. But for undead and spellcasters able to insulate themselves from consequences, an ebon tullith is an ideal additional safeguard.
Motive: Bond with undead or necromancer
Environment: Anywhere in the multiverse, singly or in groups of two or three, often in the company of undead or necromancers
Health: 6
Damage Inflicted: Minor wound (2 points)
Armor: 1
Movement: Short when flying
Modifications: Speed defense as level 4 due to tiny size; perception as level 5; stealth as level 5 (in dim or dark areas)
Combat: An ebon tullith is usually encountered already bonded to an undead creature or necromancer, visible as a shadowy veneer of protective energy. The bonded creature enjoys an additional 10 points of health from this bonding.
If the bonded creature loses those extra points of health for any reason, the bond breaks. The tullith condenses as a darting point of shadow next to the creature they were previously bonded to. On their turn, the tullith flies to a non-bonded undead creature within short range that hasn't previously enjoyed a bond with a tullith. If the tullith reaches such a target, they use their action to form a new bond with that creature, granting them the same benefit as the previous bonded creature.
If no undead or necromancers are in range, the tullith flies to the nearest living creature they can sense and attacks, attempting to touch them. If successful, an implosive blast of necrotic energy inflicts 5 points of Speed damage (ignores Armor) to the target and all creatures within immediate range that fail a Speed defense task.
Whatever the outcome, the implosive blast opens a momentary portal to the Elemental Chaos, through which the ebon tullith vanishes.
An ebon tullith is immune to necrotic and poison attacks.
Interaction: Individually, tulliths are dull and without much sense of self-preservation. But when two or more are present, they can speak to each other telepathically, and in so doing, convey a telepathic link between the creatures that are bonded to each tullith. When those bonded creatures are intelligent, some have noticed a silent, distant mental presence, observing. This has led some to wonder if these creatures are linked by a larger, hidden intelligence.
Use: A nearby cemetery has been infested with a group of ebon tulliths, rousing various undead to unusual and dangerous nighttime activity.
GM Intrusion:When a bonded creature loses their protective health shield, two ebon tulliths condense into existence instead of one.