I think Jack is WB's real son. look at the similarities between Jack and Weeble, the hair, the jolly roger (some resemblance), and the horns and beard have a certain resemblance. I think and this isnt my own theory either, but that bakkin, weebles mother, is dressing up weeble to look like Jack who is WB's real son. On top of that, the timing of their introduction was very close and they both have that mane like thing, one is jacks feather cape but it also looks similar to weebles hair.
Jack has some mask too which may be covering the trademark whiteboard chin. The both have/had long blonde hair and they have similar builds.