Smelted Chargebug is a common Artifact Creature — Insect card from Modern Horizons 3 (MH3), collector number 139. Current market price: $0.12 (foil $0.23), TCGplayer market prices via Scryfall.
Menace When this creature enters, you get {E}{E} (two energy counters). Whenever this creature attacks, you may pay {E}. If you do, another target attacking creature gets +1/+0 and gains menace until end of turn.