Wing (Super Mario Bros. Special)
From the Super Mario Wiki
The Wing is an item that appeared only in Super Mario Bros. Special. When Mario collects it, he is able to fly in the sky by "swimming" through the air, gaining aquatic properties. However, the power up is only temporary, and if Mario isn't careful, he ends up falling somewhere undesirable. It can be considered a predecessor of the P-Wing from Super Mario Bros. 3 and later games.