William Haynes, better known as Praxi or Praxi Plays, is a Floridian rapper and producer.

Praxi gained popularity with the success of his How To series on YouTube where he recreates the styles of different rappers. Some of the most popular installments focused on $UICIDEBOY$ and Ski Mask the Slump God.

In November 2019, Praxi released his debut project, Mood.