Prodigal Sorcerer
Tim is a nickname for the card Prodigal Sorcerer. The card got this nickname because it is a wizard that can damage stuff on command, akin to the character Tim in the movie Monty Python and the Holy Grail, and the art in later printings was changed to make the homage more direct. Tim is also now used as a verb to discribe the action of dealing one damage.
Planar Chaos
Prodigal Pyromancer introduced in Planar Chaos is a timeshifted version of the Prodigal Sorcerer. The card is more fitting in red, speculation is it will be reprinted in a core set eventually.