Cuddlebuns is one of the Tiny'mon in the Tiny'mon world. Due to Cuddlebuns' inability to be trained, She is known as the lowest-ranked Tiny'mon ever. According to Johnny, Cuddlebuns is untrainable and can barely fly. Cuddlebuns evolves into Screechereen after Mary sweetly kissed her when she felt bad for her.
Cuddlebuns might be based off of the Pokémon Magikarp, the weakest Pokémon, that evolves into the strong Gyarados, which might be what Screechereen is based off. Despite this, her design is clearly based on Pikachu.
Weirdly she was called a "he" in her debut episode before it was confirmed she was a female. It's possible it could've been a different Cuddlebuns however.