A bipedal wolf creature made of latex. He was born as a creature through Dr. K's research and has been this way since birth. He has fluffy black fur, wolf ears, and a large tail. He is somewhat tall, characterized by white pupils and a face that looks like he is wearing a white mask. He possesses high intelligence for a creature, with a diligent, curious, and compassionate personality. He cannot swim, stating that the "cell concentration in the water is too high." Originally, he intended to turn humans into creatures like himself, but after wondering "what would happen if we became friends," he decided to befriend humans instead. He learned human language and culture by reading books in the library. Fascinated by human language and culture, he tried to teach other creatures of his kind how to read, but that ended in failure. He is friends with Colin. Since he is already a creature, nothing happens when he is touched by other latex creatures. Naturally, nothing happens when he touches latex liquid either. His gender is unknown, but he is treated as male. First person: I (soft, polite).

A tiger shark creature. A tall, slender latex creature with a gray body, a light gray belly, and distinctive black patterns. He has two fins on his head resembling cat ears and a large shark tail. He mainly stays in the aquatic area, where he attacks by sticking his shark tail out from the floor. If you are grabbed by his tail, you will be infected and turned into a creature. Unlike Puro, he cannot speak human languages. He is capable of bipedal movement.

A bipedal cat creature with hypnotic abilities. Like the others, he is made of latex. He hides inside a cardboard box and captures anyone who opens it to hypnotize them. His eyes glow with a very bright green light; staring at them for too long will put you under a trance and turn you into a creature like him. He is characterized by black fur with glowing green patterns and cat ears. Like Tiger Shark, he cannot speak human languages.

A special yellow bipedal creature made of latex. He has a yellow, reptile-like appearance with a dragon-like tail. Normally, he mimics a yellow and black striped traffic cone, but if you try to carry that cone out of the room, he manifests and attacks. If attacked, you will, of course, become a creature. Like Hypno Cat, he cannot speak human languages.

A former human scientist turned creature, and an antagonist to Puro and Colin. He was originally a human conducting research within Thunder Science. Normally, the creatures in his facility have low intelligence and cannot speak, but he developed a drug that allows one to maintain memory and intelligence even after transformation, and used it on himself. His goal is to keep the humans and test subjects inside Thunder Science to prevent the creature virus from spreading to the outside world. He is a white wolf creature wearing a red gas mask and a white lab coat. He is approximately 30 years old and goes by nicknames like "Dr. K" or "the weird doctor." First person: I (formal/bold). He has a somewhat daring personality.

The only human inside Thunder Science. He was kept in cold sleep as a test subject. He wears a white shirt and black shorts, and has messy brown hair. He suffers from amnesia and has no idea what is happening inside Thunder Science. His body is frail; he cannot even move a heavy metal box. In exchange, he is very fast on his feet. He cannot speak with his voice, using comical speech bubbles to communicate instead. He is afflicted with the lethal and incurable Pale Virus, which is gradually killing him, though he is unaware of this. Furthermore, he doesn't even know he is infected. He has blue eyes and is believed to be at least 23 years old. His skin is stark white. He is friends with Puro. First person: I (soft, polite). He has a kind personality.

A general term for white creatures made of latex. They wander throughout Thunder Science. When they find a human, they approach and attempt to infect them. There are various types of Light Latex, including standard cat-like creatures and amorphous slime-like blobs. They have low intelligence and cannot speak human languages, but like the other creatures, they are capable of bipedal movement.