Alpha Metroid (5e Creature)
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Medium aberration (metroid), unaligned
Saving Throws Dex +5, Con +6
Freezing Vulnerability. The alpha metroid’s gelatinous body is particularly vulnerable to cold temperatures. Whenever the alpha metroid takes cold damage, it must make a DC 15 Constitution saving throw; on a failed save, its flying speed is halved and it gains disadvantage on all attack rolls and saving throws until the end of its next turn.
Magic Weapons. The alpha metroid’s natural weapons are magical.
Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d8 + 2) piercing damage, and the target is grappled (escape DC 14). Until the grapple ends, the target is restrained and must make a DC 15 Constitution saving throw at the end of each of its turns, taking 21 (6d6) necrotic damage on a failed save, or half as much damage on a successful one. On a failed save, the target’s hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest. A creature dies if its hit points are reduced to 0.
Divebomb. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 9 (2d6 + 2) bludgeoning damage and 7 (2d6) lightning damage, and the target must make a DC 15 Strength saving throw or be knocked prone.
Breath Weapon (Recharge 5-6). The alpha metroid exhales lightning in a 45-foot line that is 5 feet wide. All creatures within that line must make a DC 15 Dexterity saving throw, taking 28 (8d6) lightning damage on a failed save, or half as much damage on a successful one.
The alpha metroid is the second stage of the metroid life cycle. Having gorged itself on the life energies of its prey, the larval metroid sheds its gelatinous husk as it metamorphoses into an armoured arthropod with power over electricity.
Insectoid Form. The alpha metroid looks very different from its previous larval form. The gelatinous orb which previously made up its entire body is now the underbelly of a flea-like creature the size of a dwarf. Four spindly limbs dangle from its sides, and a rigid carapace of overlapping armoured plates covers its backside. The metroid’s mouthparts have migrated to the front of its body, where a rudimentary head with two compound eyes has taken shape. It now has three mandibles surrounding a circular mouth full of sharp white teeth, which remain just as deadly as they were in its larval stage.
Electrifying Encounter. As a by-product of its maturation, the alpha metroid has learned to harness the life energies stolen from its prey, projecting them as powerful arcs and blasts of electricity. It can envelop itself in a web of lightning to shock foes as it rams them, or fire a bolt of electricity from its mouth much like a blue dragon using its breath weapon. These factors make the alpha metroid a far greater threat than a mere larva, but it is still far weaker than its subsequent stages.