A platypus enrolls into CDMS, and he keeps rubbing into everyones face that he is a brain-sucking alien. Adam refuses to believe this, but the animals have reason to believe from various signs.
| Actor | Role |
|---|---|
 Tom KennyJake Spidermonkey (voice) | Jake Spidermonkey (voice) |
 Nika FuttermanAdam Lyon (voice) | Adam Lyon (voice) |
 Grey DeLisleLupe/Ingrid (voice) | Lupe/Ingrid (voice) |
 Rick GomezSlips/Windsor/Teddy Truman/Daniel Calamari (voice) | Slips/Windsor/Teddy Truman/Daniel Calamari (voice) |
 Gilbert GottfriedRick the Platypus (voice) | Rick the Platypus (voice) |
 Maurice LaMarchePrincipal Pixiefrog / Mr. Mandrill (voice) | Principal Pixiefrog / Mr. Mandrill (voice) |
 Phil LaMarrBull Sharkowski (voice) | Bull Sharkowski (voice) |
 Cree SummerMrs. Tusk (voice) | Mrs. Tusk (voice) |