A Moroccan Arabic (Darija) expression used to convey disbelief, surprise, or astonishment. It can also indicate amusement or irony depending on the context. It has a lot of synonyms like "Wa 3la fassfara", "Wa 3la 9wada", but this last synonym comes with a frustration tone in it.
Person 1: I just found out that Rachid is in DAKHLA!
Person 2: Wa 3la Bajbaja! He's really crazy!