Elvish Spirit Guide

The companion to Simian Spirit Guide, and the green half of a design pattern Alliances quietly invented: a creature that doubles as a one-shot ritual you never have to cast. The 2/2 body for three mana is irrelevant; the card is bought for its alternative use, exiling itself from hand to produce a green mana before turn one ever resolves. That window is the whole point. Most acceleration costs mana or a card or a slot on the battlefield where it can be killed; this asks only that you give up the creature, and it does so at any moment a cost needs paying, including on your opponent's turn or in response to something on the stack. What keeps it from spiraling into ramp is the shape of the payoff: one green, once, no engine, no recursion. That makes it a pure tempo loan rather than acceleration, and the decks that have wanted it are the ones counting mana in fractions of a turn, where arriving a beat early on a combo or a hard-cast threat is worth burning a card to do. Its logic anticipates the pitch spells that came later, Force of Will chief among them: the green is free at the table because you paid for it in your opening hand, spending a card to buy tempo instead of spending mana to buy a card.