Homebrew Flesh Plasmoid Species Details

It grows more powerful with each victim it takes. Immune to necrotic damage, but weak to fire damage. Every time it changes shake it makes a wet squelching sound. Smells rotten, but never decomposes. Can form claws and spines made from bone anywhere (on it's body). Claws do peircing damage and spines to slashing damage. Half undead, it's brain does not produce fear. Unlike other plasmoids, it has vitals. If you hit the vitals it still takes a while to die. Immune to bludeoning damage. Resistant to slashing damage. 

Flesh Plasmoid Traits

Immune to necrotic and bludeoning damage. Natural hits do slashing, peircing, or bludeoning damage. Weak to fire and electricity, but resistant to slashing damage.

Amorpheos

This ability allows all plasmoids to reshape their bodies and in this specific case it can make natural blades out of bones. The more kills it makes the more blades it can make. It can still create morphs up to 10 feet long, and it can completely reshape their body. 

Immunity to necrotic and bludeoning damage

No straight bludeoning attacks can harm it. This includes falling rocks, hammers, clubs, etc. Nothing necrotic can damage it. All spells, enchantments, and any matter of death necrotic damage does no harm.