This (person/thing) is now not, a (person/thing) should fill its slot
Transforms a person or object into anything
The same spell can be used, or spell improvisation
The spell is first used by Justin to change a guinea pig into a dove. He performs the spell perfectly.
Alex attempts the spell, but her guinea pig instead changes into a brick. Jerry tells her it's because she wasn't concentrating.
When Max casts the spell, he accidentally says 'snot' instead of 'slot'. The guinea pig still transforms into a dove, but due to the flubbed word, the dove sneezes 'snot' onto the container.
Alex uses the Transformation spell on her parents when she was about to get caught trying to hide her report card. She panics and turns Jerry and Theresa into guinea pigs.
Justin uses the spell on the Theresa and Jerry guinea pigs to transform them back into humans.
Justin turns Professor Crumbs into a guinea pig possibly using this spell. He is not heard saying anything, so either he's able to do wizardry without spells (even though he's used spells throughout the episode), or he whispered it. He does not turn Professor Crumbs back using Transfiguration spell. He uses an improvisation.