Special Guest Stars Lily Tomlin voices Professor Fizzle Nathan Fillion voices Axle ValveStuck Martin Short voices Tony Tennelli Catherine O'Hara voices Aunt Tennelli Catherine O'Hara voices Teresina Tennelli Jay Baruchel voices Dr. Tillage Guest Stars Birva Pandya voices Jyoti Lynsey Pham voices Wanda Leke Maceda-Rustecki voices Carlos Kaden Stephen voices Tim Gabby Clarke voices Dorothy Ann Matthew Mintz voices Ralphie Mikaela Blake voices Keesha Co Starring Ana Sani voices Additional Voices Annelise Forbes voices Additional Voices Lilly Bartlam voices Additional Voices Stuart Stone voices Additional Voices Marcus Craig voices Additional Voices Martin Roach voices Additional Voices Kevin Vidal voices Additional Voices