If you've been following Magic for years and years, you know who this is:

Corrupted Conscience | Art by Jason Chan
That, of course, is Karn, who has appeared on cards in a wide variety of sets. Behold!
Tempest

Stronghold

Sift | Art by Pete Venters
Exodus

Treasure Trove | Art by Michael Sutfin
Urza's Saga

Karn, Silver Golem | Art by Mark Zug
Urza's Legacy

Miscalculation | Art by Jeff Laubenstein
Apocalypse

Jaded Response | Art by Matt Cavotta
Mercadian Masques

Karn's Touch | Art by Alan Pollack
Tenth Edition

Legacy Weapon | Art by Terese Nielsen
Now, we've got a surprise for you. There's one more set that had Karn in it, but you've never seen it. That, of course, is Unglued 2, which got cancelled and then cannibalized for Unhinged ideas. And in Unglued 2, there was a card called "Jeopardy," which was illustrated by Phil Foglio. So here, for what is probably the first time anywhere, is that piece of art!
Unglued 2

Jeopardy | Art by Phil Foglio