All Grown Up! - Season 3 Episode 4
Curse of Reptar

After Stu sells an invention, he tells the kids that hes splurging on a built-in swimming pool. While digging up the yard, the construction crew unearths the Rats old mechanical Reptar toy. The kids fondly remember it, but decide to throw it away, until, during an electrical storm, they become convinced that theyve angered Reptar. They ultimately decide to rescue the toy, and realize that, although theyre growing up, they cant forget their past.