Celesteela (5e Creature)
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Gargantuan aberration, neutral
Beast Boost. When Celesteela reduces a hostile creature to 0 hit points, the DC of its leech seed effect increases by 3 and the damage dealt per turn increases by 2d6. This bonus is cumulative, but resets when Celesteela takes a long rest.
Multiattack. Celesteela makes three attacks with its Flash Cannon.
Flash Cannon. Ranged Spell Attack: +6 to hit, reach 5 ft., one target. Hit: 17 (4d6 + 3) force damage.
Leech Seed. Celesteela targets one creature within 60 feet of it that it can see. The target must make a DC 14 Constitution saving throw. On a successful save, the creature can't be targeted by Celesteela's leech seed for 24 hours. On a failed save, the creature is infected by a leech seed. While infected in this way, a creature takes 14 (4d6) necrotic damage at the start of each of its turns, and Celesteela regains the same number of hit points. A creature can repeat the saving throw at the end of each of its turns, ending the effect on a success. If the saving throw is successful or the effect ends for the creature, it can't be targeted by Celesteela's leech seed for 24 hours.
Celesteela is an enormous creature that appears to be made out of metal, despite the fact that it can fly and is alive. It attacks by shooting bursts of magic, as well as being able to summon seeds that drain the health of those they touch.