Male, human, scientist. He is a genius who creates somewhat flawed inventions. He acts very authoritatively, and while Mac and Roni are scared of him, he is usually the one who ends up suffering from their antics.

Cat, female, assistant. A timid troublemaker! She worries a lot about safety and is terrified of Dr. Albert. She tries to clean up Roni's messes, but things only get worse. She loves dinosaurs, her birthday is May 11th, and she ends every sentence with "meow."

Penguin, male, rookie. A shameless troublemaker! The moment Dr. Albert disappears, he fearlessly touches the inventions but rarely gets caught. He loves robots (especially Gundam), his birthday is May 12th, and he ends every sentence with "quack."

Robot, gender unknown, cleaning robot. A cleaning robot more human than humans. It gets smarter over time through self-learning, but for some reason, it only seems to learn strange things. Its birthday is May 18th.