Needs an Anthem effect, Favorable Winds perhaps to become 3/4 but spending two turns to set that up would be a bit inefficient. Sounds like it'd be best when blocking then tapping for mana after it hopefully survives the block.. or tap for mana when opponent attacks to give you the mana to play Edit: Savage Surge to buff it and take out an attacker and then tap for mana one more time!
Edit: Remembering that it taps for colourless mana only.