Birdie is a character from the very first Street Fighter. He is a criminal who seeked to join M. Bison and Shadaloo. Despite having a knife, he only uses his chains and strong body in battle.

He was previously diagnosed with Anemia (iron deficiency) which led him to participate along with Eagle in the 1st World Warrior tournament directed by Sagat in order to gain the prize and find a cure, he ended up losing it because of Ryu but successfully got a cure and beated it, and his chains symbolize that.

His normals are slow but cover many spaces and, although not a much as the rest, you can even do Chain (funny) Combos with him. He's essentially a tank character, with a bit of grappler (Murderer Chain) and charge (Bull Head and Bull Horn, essentially rush) specials. For super combos, he has The Birdie, which is a more powerful version of his charge commands that in Level 3, if the 3rd hit connects, 2 more hits are added. He has 2 variants of his Bull Revenger (Grab super combo), one for close range and one for long range.

His taunt has a hitbox, yeah.