Shedinja is as of yet the only Pokemon that possesses the Wonder Guard ability. It will always have it.
It's a good ability (like, incredibly good) but it only has it because Shedinja always have 1HP, regardless of stats, IVs or EVs. Shedinja only really has 1HP during it's 'forever life span' and no other Pokemon is gonna have that either, so don't expect it to appear on other Pokemon if you want a Pokemon with that ability.
Hope I helped. :)