Rapid Augmenter is a rare Creature — Otter Artificer card from Bloomburrow Commander (BLC), collector number 38. Current market price: $0.41, TCGplayer market prices via Scryfall.
Haste Whenever another creature you control with base power 1 enters, it gains haste until end of turn. Whenever another creature you control enters, if it wasn't cast, put a +1/+1 counter on this creature and this creature can't be blocked this turn.