If there had been flashbacks involving Quetzal, Sid, or Scallywag in younger years, I believe either Danny McKinnon (the voice of Max), Noah Reid, Cole Caplan (Olie Polie from Rolie Polie Olie), Kathleen Barr (Wheezie; yes, Barr has voiced boys in other programs like Henri from Liberty's Kids), or Lenore Zann would have voiced either of those characters as boys.