Kellie Shanygne Williams dons the iconic suspenders, high-water pants, and thick glasses.
The episode (Season 4, Episode 10) is a fan-favorite Christmas special where an angel grants Laura a wish to see what life would be like if she were the nerd and Steve Urkel were the "cool" one.
After Laura says she wishes Steve knew what it was like to be her, a guardian angel named Tyrone appears. He uses a bit of "Urkel-magic" to swap their personalities and social standings. The Transformation: