Beepis

A head parasite from the Body of Glorg that duplicates every passive the wearer has. Beepis's CopyPassiveSlot effect mirrors all passive abilities during battle, effectively doubling whatever passive build the cat has accumulated. The tradeoff is significant: AllSpellsCostCharge converts spell costs to a charge-based system and ManaCostReduction applies but spells are limited to once per turn, constraining high-frequency casters. A powerhouse for passive-stacking builds that rarely need to cast multiple spells in a single turn.

CopyPassiveSlot is one of the strongest effects in the game on the right cat. Every passive — whether from items like Eye Worm, Scabies, Cooties, or mutations — is duplicated and active simultaneously. The once-per-turn spell limitation doesn't matter at all if you never cast spells, making Beepis ideally suited for melee or passive-only builds that accumulate effects through attacks and reactions rather than spell use.

Equip Beepis on a cat who has stacked multiple high-value passives across their items and mutations. A Butcher or Monk with six passives running simultaneously after Beepis doubles them becomes an absurdly efficient combat machine. The one-spell-per-turn limit makes it a poor choice for Psychics or casters who need multiple casts per round. Wait until late in a run when passives are fully loaded before equipping Beepis to maximize the value of its duplication.