The only times we've met Jack was at the Pirate Princess parties. He was in an old Disney restaurant over in Adventureland. I don't think he's a regular character at WDW but he is regular at Disneyland.
We met them at DHS last year in the ???Animation building???
The incredibles are usually there too. My guess is this year it will be Wall E. That area changes to match whatever movie is "hot" at the time.