Mana-Charged Dragon is a rare Creature — Dragon card from Commander 2011 (CMD), collector number 129. Current market price: $1.19, TCGplayer market prices via Scryfall.
Flying, trample Join forces — Whenever this creature attacks or blocks, each player starting with you may pay any amount of mana. This creature gets +X/+0 until end of turn, where X is the total amount of mana paid this way.