After the spa closed, Derrick returned to the spa. He snuck out of his bed while his family was asleep and went to the spa to investigate the pool of mud, hoping to restore himself to normal.
"I hope this works" He said, grabbing a clump of mud, rubbing it on his face. Derrick then felt strange, he lost some height, he felt younger, he was 5. He also felt his ears become round. He started thinking more like a kindergartner.
"Mud Parwtee!" He said, in a toddler accent and lisp. He jumped into the pool, splashing and rubbing mud on himself, his ears moved to the top of his head, he started to feel itchy, but he didn't notice.
Derrick began to grow fur, his nose changed color and grew into a muzzle, whiskers also grew. He was enjoying the mud pool, he was laughing, his voice was getting higher pitched. He resumed shrinking, age stripping off.
Grey fur began growing all over his body, his eyes dilated, he was 3 years old. His hands changed shape, losing a digit, his feet experienced the same thing, but they also got longer. His legs shifted, going into a digitigrade position, he began to feel more comfortable on all fours. He was still laughing, until he felt a piercing at the end of his spine, his tail grew in. He kept shrinking as his fur finished growing in, he stopped regressing when he was a 1 year old baby, but he kept shrinking until he was 2 inches tall. He exited the pool, realizing that everything was huge. He was a mouse.
"So you think you can restore yourself by playing in the mud, that never works, you become a 1 year old mouse that way, have a great time on the streets, scavenging for food." A voice said.
Surprised, Derrick looked behind himself to find a massive version of Hebe.