Professor Fleeber is considered the world's top expert on sealians. However, as he reveals to Princess Amber and Princess Sofia, everything he wrote about sealians is based on stories he heard from sailors who sailed through the Stormy Triangle. When he found out that nobody had actually seen a sealian, he sailed to the Stormy Triangle to find some sealians and learn about them.
Professor Fleeber makes his debut appearance in "Her Royal Spyness". He first appears when Princess Sofia and Princess Amber arrive on his island. The two girls tell him that their mother was lured away by a sealian and he agrees to help them find her. When he spots some sealians, he supports Sofia's decision to follow them. Suddenly, a storm starts blowing and blows the girls into a ship where they find their mother. Fleeber gets on board and reveals to a frightened Sofia and Amber that the "sealian" is really a human. Suddenly, the sealians from earlier arrive and lead them out of the storm. Fleeber meets the other sealians, who agree to let him learn about them.