Dexter's Laboratory: Ego Trip (1999)

Plot

Confronted by robots intent on eliminating "the one who saved the future," Dexter activates his time machine to uncover his heroic legacy. Easily dispatching the attackers with his lab’s gadgets, he grows curious about his significance. His first destination reveals a lanky, timid version of himself stuck in a dull office job under the domineering Mandark, who is now wealthy and accomplished. During their time-travel escapade, young Dexter inadvertently exposes plans for the "Neurotomic Protocore," allowing Mandark to swipe the schematics while they leap into the future.