Dr. Somnambulo (voiced by Frank Welker) is a sleep therapist. An insomniac Jon Arbuckle, upon seeing a commercial for Somnambulo, seeks help from him. Due to an error, Jon's ability to sleep is controlled by Odie's barking. Somnambulo eventually undoes the hypnosis.
- His name is likely based on the word "somnambulate", which is the Latin word for sleepwalking.