This idea was scrapped long ago. I'll keep adding to it just in case.
If anybody wants to borrow a monster for their series, then go ahead.
Drillbit is a giant mole with a drill for a snout. Needless to say, he is very good at digging. He is the first monster ever seen.
Rocky the Earth Dragon
Rocky is a hasty Earth Dragon who crushes anything in it's way. He has abilities to spit, hurl, and eat rocks. He is a bit sensitive about the fact that he doesn't have wings.
Robo-Moose is a Moose/Robot hybrid! Using his laser eyes, his shape-shifting arms, and his jet wings, he can take down any opponent or just clean up aroudn the house
Deejay is a canine-like creature covered in thick, blue fur. It appears to be half-mechanical as it has a giant speaker in his head that allows it to create massive soundwaves. On top of that, it also has ice breath.
Markie is a tablet monster, meant to take control of anything it touches once in liquid form. Its main goal was to control the entire Slusher building, but instead became a mere pencil. He was granted to power to draw horrendous creatures to life, though.
Doppeldicer is a robot who was created to be a mincer, and a pretty mean one at that! His mechanical wings are actually chainsaw blades, and his feet have claws and ninja shurikens strapped onto it. He's even got a metal blade on his chest and a helmet with three sharp horns! And also, he's painted all yellow.
Bloob is a Blue Blob, as his name suggests who always sports a sullen expression. He was created to destroy Seth, being immune to his atomic breath.
King Coiler is an enlarged Corn Snake's head strapped onto a robotic replica of a King Snake's body, hence the name. His spinning robotic arms and and fully functional tail can create tornadoes.
Akkorokamui is a giant, 12 legged Octopus with crab claws on the ends of his tentacles. Most likely a mutant. He alse gained the ability to breath fire.
Llib is the evil version of Bill. Nothing much more to be said.
Don't be fooled by his name, Fleshog may look like a normal mutant hedgehog, but under all that artificial fur that keeps him safe from common circuit frying, he's really 100% robot. Using his razor-sharp claws as his best attack, almost nobody near him is safe.
Moc is an alien that crash landed in Slusher.He appeared to be a cute baby stickman at first but was later revealed to be a collosal monster who will destroy anything that is in his path!
He is a giant fish with He has sharp teeth that is 200 times sharper than a knife. He appears to be ess dense than air, as he can float around at his choice.
Tiny square turned cube monstrosity, Agar is a gluttonous cube which started small but munched enough to grow bigger than a house! His appetite is rivaled by none (except maybe Stickirby) and his tongue is a real threat.
Begonia is a flower and is the only monster to have appeared twice. The first time, she spewed gas to force Fyonna and Seth to fall in love. After that, she grew to an enormous height and was promoted to "allergy" monster spreading pollen all over Slusherville, making the denizens of Slusher too sick to fight.
Takeout was supposed to be Redster's calamari lunch from a nearby sushi restaurant, but he turned it into a giant, malicious Octopus which went after Whietick and Seth.