He is a robot that worked as a maid at Yusaku's house.
Built and programmed by Yusaku, Roboppy is very loyal and respectful to him. Yusaku cares and visibly has a fondness for his house cleaning robot, as he warmly smiled and petted Roboppy affectionately as seen in his flashbacks. Roboppy does describe Yusaku as being "a little cold hearted."
In Season 3, he is the secondary antagonist after becoming an android working alongside Ai.
Roboppy uses an "Appliancer" Deck centered on Link Summoning. His Main Deck monsters focus on swarming and toolboxing and often revolve around monsters of the same name. His core strategy is to Link Summon as many "Appliancer" Link Monsters as possible, an easy feat since most of his Link Monsters are of low rating.
His Link Monsters despite being weak on sheer ATK value, gain powerful effects depending on whether they are Co-Linked or not. Due to their low Link Rating, Roboppy is able to Co-Link many of them easily. He also uses cards to be able to change their field position so that they are no longer Co-Linked, according to his needs. Roboppy also runs multiple cards that can Special Summon his "Appliancer" Link Monsters during the Battle Phase, both to increase the number of attacks he can make and reuse their effects.