"Derek", better known as "Derek the Stunt-Bat", is a retired stunt-bat that was brought by Heinz Doofenshmirtz so he had an easier target for his latest inator.
This backfired since Doofenshmirtz just remembered he had a minor fear of bats. Once Derek flew to St. Louis with Doofenshmirtz, Perry used the inator on him again, causing him to return to his normal form.
Physical Appearance[]
In his normal form, he looks like a normal bat.
In giant form, his appearance gains a more ferocious and dangerous look: his teeth get sharper and larger and his eyes become narrower.
Appearences[]
- "Face Your Fear" (First appearance)