Birds of Paradise

Every fixer printed since has chased the rate this card established: a one-mana body that taps for any color, with flying stapled on so it dodges the ground-stall combat math that would otherwise make a 0/1 a liability. That evasion is the part modern designers no longer give away. The successors all pay for some piece of the package the original did not: Noble Hierarch trades color flexibility for a tribal tax and an exalted upside, Deathrite Shaman needs a graveyard to fuel its mana, Ignoble Hierarch carries a creature-type restriction. Each one reaches back toward what Birds of Paradise was allowed to do unrestricted and clips a wing off it. The 0 power matters too: it confines the card to pure utility rather than ever threatening as a beater, which is the trade that lets the five-color tap ability sit on a one-mana frame without warping combat. Reprinted in nearly every Core Set through the early Modern era, it became shorthand for "green is the ramp color" at a structural level: green gets the best one-mana fixer, and every other color gets a worse version or none at all. It did not invent mana acceleration (Llanowar Elves shared its Alpha debut), but it set the ceiling the color pie has been negotiating around ever since.