Leonard was born and raised in Metroburg. He was a student at Secret Academy of Superpower Studies (SASS) along with Max and Phoebe Thunderman. His "superpower" is a metallic butt which allows him to crush anything he sits on. Back in SASS, Max gave Leonard the nickname "Metalbutt" and often teased him. He once got stuck on the wall after Max magnetised it to attract his metal butt.
In Back To School, when the Hero League forced Phoebe and Max to go back to SASS to retake their superpower assessment test, they're shocked to find Leonard as Mr. Silver Eagle's teacher's assistant. Leonard vows to revenge against both of them - Max for pranking him and giving him nicknames, and Phoebe for writing nothing on his yearbook page. He knew that if the Thunder Twins fail the test, Phoebe would never become a superhero and Max would end up in a junior jail. Leonard used his metal butt to make Chester accidentally shoot Mr. Silver Eagle with his porcupine spines. This gave Leonard the perfect opportunity to sabotage Phoebe and Max.
First, Leonard destroyed the twin's phones by sitting on them so that they couldn't report him to President Kickbutt. For their first test, he gave them items that he knew couldn't be used to build a weapon against the robot, but Max used his smarts to overcome that. He then decided to tie them up for the next test so that they wouldn't be able to do anything. For the last test, he planned to destroy them with lasers by turning up the lasers while Max and Phoebe were trying to rescue a dummy. Keely and Jocelyn tried to save the twins but accidentally magnetised the SASS logo, causing Metalbutt to be stuck on the wall. Phoebe and Max then risked their lives to save Leonard from the lasers, despite him not trusting them. Max apologized for having pranked him and called him names.
Mr. Silver Eagle came back, figured out what had happened and demoted Leonard to the third-grade.
Powers and Abilities
- Metalbutt - Leonard's special power/ability is that he has a metallic butt which he can use to crush things.
- He uses a screwdriver to go to the bathroom.