Bee Mario is a form Mario took after collecting a Bee Mushroom, which is first found in the Honeyhive Galaxy, in Super Mario Galaxy. When Mario takes this form his hat changes to better resemble a helmet with antennas and his overalls become yellow with stripes and he will grow a stinger and small wings, which allow Mario to take flight in a similar manner to a bee for a short time (however Mario sacrifices all of his jumping skills). Mario will also be able to climb honeycombs and walk on flower petals and clouds. Mario will lose this form by taking damage or by touching water. By collecting coins in mid-flight, Bee Mario’s fly gauge will slightly refill.
Info from: Mario Wiki
By: André, finished picture by: Louspierce