Hardbristle Bandit

The trick with a mana dork is that it taps once and then sits there, useless, until your next untap step. This one rewrites that constraint by tying its untap to an action the deck is already taking: every crime (a removal spell, a targeted burn, an activated ability aimed at an opponent) untaps it, so the body that produced ramp early keeps producing it mid-turn as your spells resolve. The design logic converts interaction into acceleration: cast something that touches an opponent, get the mana back, cast something else. Limiting the untap to a single trigger per turn is what stops cheap-enough crimes from spiraling into an infinite loop, keeping this a single extra mana rather than a full engine. And the mana it hands back is any color, not just green, so the crimes that untap it can be off-color removal or interaction the deck otherwise could not afford on curve. It is a small creature doing a small thing, but the mechanism is a genuine wrinkle in how mana creatures behave, rewarding a deck built to needle opponents repeatedly over one that plays out its own board in a vacuum.