Toph Bei Fong

Toph Bei Fong, usually referred to as simply Toph, is an Earthbending master. Blind since birth, Toph was constantly condescended to because of her disability and stature as an innocent little girl, especially by her overprotective parents. Upon discovering Badgermoles, earth-dwelling animals who were blind just like her, she learned seismic sense through them - the ability to use Earthbending as an extension of her senses and effectively give her "sight" through vibrations in the ground.
Known as the "Blind Bandit", she mastered Earthbending through her own style and developed a tough-guy personality, becoming infamous by winning underground Earthbending tournaments behind her parents' backs. Initially uninterested, she chose to leave behind her old life and travel with Avatar Aang and friends to be his Earthbending teacher. Toph's mastery over earth, especially with Metalbending, as well as her unique personality, proved her to be a valuable addition to the Avatar's group.