Echoing Assault is a rare Enchantment card from Bloomburrow Commander (BLC), collector number 24. Current market price: $0.33, TCGplayer market prices via Scryfall.
Creature tokens you control have menace. Whenever you attack a player, choose target nontoken creature that's attacking that player. Create a token that's a copy of that creature, except it's 1/1. The token enters tapped and attacking that player. Sacrifice it at the beginning of the next end step.