This scene comes from the Season Finale of Aaron's Adventures Advanced episode King-Sized Problems.
After spending some time with The Numbers Club, they suddenly encounter Pitch and hear about what The Kingdom of Darkness is up too, he then turns to Yue and reveals a long lost secret about his past.
Yue: What's so funny?
Pitch: If you turly want too know.
Pitch the creates a magical orb out his nightmare sand and shows Yue something.
Pitch: Yes, that happens to be a long lost secret kept from you.
Yue: You mean, their are more like me?