The Mantis was the disguise of Professor Greer. The Mantis was an insectiod type of creature who was apparently 7 feet tall according to Shaggy Rogers. The Mantis came out of the ferns and chased the mailman. When Scooby-Doo gave the flowers to the Mantis, it sneezed. Professor Greer told the gang about the Praying Mantis. The Mantis continued to chase the gang, even taking Daphne Blake hostage. When it was finally trapped, the three suspects ended up appearing. The Mantis was revealed to be Professor Greer.