A syringe-like device that injects specially formulated mutagens into a creature's bloodstream, temporarily altering their physiology.

Malformation Serum

Recharge 33%, std, melee; you inject a target with a mutagen that causes rapid mutation. A horrible mutant "limb" sprouts from them, complete with at least one eye and a sort of mouth. This limb can, at your direction (using a swift action to give it commands), act according to your wishes, not those of its host. The limb has AC 10 + host Dex bonus (typically doesn't benefit from armor, as armor doesn't morph along with the limb). It has HP equal to a medium damage roll; all damage it suffers, the host suffers too. At zero HP, the limb falls off and dies.

The limb's capabilities are:

• Attack: make a melee attack using the host's unarmed attack, or, if armed, the weapon's stats.
• Retrieve and Item: grab an item within reach, including items held or worn by the host. If held, contest Strength with the host to seize it.
• Interfere: attempt to block any physical action the host takes. This command essentially grants the limb a reaction each round to cause disadvantage to one Strength, Dexterity, or Constitution based action the host takes.
• Grapple: attempt to grapple a target within reach, using the host's unarmed attack stats. Can grapple the host themselves, which has the normal effects of grappling, except that the host isn't immobilized.
• Cast a Spell: if the host has spells, the limb can attempt to cast one of them, using the host's spellcasting ability and energy. It is a horrible mutant limb, so it suffers disadvantage to the check used to cast the spell, and if the final roll is a natural 10 or less, the spell simply fails.

Mutagenic Boost

Recharge 33%, std, melee; you inject a target with a mutagen that temporarily enhances the subject by infusing their DNA with that of powerful creatures. The effects last 3 rounds.

• Bull's Strength: subject's size increases by one category, and they gain a pair of horns (which can be used as a melee attack inflicting heavy piercing damage). They gain +8 Strength, but -2 Dexterity.
• Cat's Grace: subject gains +8 Dexterity, but -2 Strength. They also gain a prehensile tail that can be used to perform simple Dexterity actions like tripping or grabbing an item. They can run on all fours, gaining +4 movement squares; they also gain a Jump action equal to their new movement speed.
• Bear's Endurance: subject gains +8 Constitution, but -2 Intelligence. They grow one size larger and sprout thick, furred skin that grants them temporary hit points equal to a heavy damage roll.

Other ideas

• Mutate enemy into useless blob (rank 3/4)