Rainbow Crow

Color identity as a toy. The flying 2/2 body is filler, but the repaint ability turns this Bird into a chameleon for every color-matters effect that ever cared what was sitting on the battlefield. Want to dodge a removal spell that cannot touch black creatures? Make it black. Want to satisfy a protection-from-blue check or trigger something that rewards a green permanent? Pay one and switch. Note the limit that keeps the gag honest: it becomes a single color of your choice, not all of them at once, so each repaint is a one-color commitment you have to read the board to make correctly. The function predates the formal color-identity rules by years; what the card actually exploits is the older convention that a creature's color was a checkable property other cards interrogated, and that this one could relabel itself on demand. Timing is the whole appeal: because it is an ordinary activated ability with no speed restriction, you can pass priority, watch the opponent commit a color-restricted removal spell or lock in a combat assignment, and then respond by changing colors out from under it. It was never a Constructed staple and was not meant to be; the design is closer to a flavor pun (a bird named for the rainbow that can wear any single hue on demand) given just enough mechanical teeth to answer a color-hoser in the right pocket of a game. The name carries most of the weight; the ability is the punchline.