My son was playing creatures village and he put his norn in a new area and he says it turned into a mouse. Is there a way to get his norn back?

Hi, I purchased Creatures Village for completeness but have didn't play it.
According to Creatures Wiki, this happens in adventure mode in Creatures Village, I copied the related content below:
"In the mine shaft there is a closed opening beneath the grappling claw. Clicking it will open it allowing your norn to slip through. Here you can access various machines to change a norn's appearance, pigment tint, their hair and even into a different creature. Simply open a door and close it to place the norn inside. With the creature transforming machine, select the blue liquid and press the switch to turn your norn into a mouse. The mouse will enter a secret passageway containing a jigsaw piece. Place the mouse back into the same machine to transform it back. "