Ditto 2 is actually a Shiny Pokémon. The Ditto was quite a pranking Pokémon, as it went to transform (along with Ditto 1) into some of Dawn's, Ash's and Brock's Pokémon, though Narissa caught them in this act. Later, Narissa had a battle with Ash's Infernape, transforming into Infernape and learning his moves, though Infernape won. Brock displayed a match against his Happiny and Sudowoodo, which Ditto 1 and 2 copied their Pound and Hammer Arm.
When Team Rocket stole this Ditto and Ditto 1, they transformed into Meowth and Wobbuffet to stall them while Narrisa and the heroes arrived. In the battle, Ditto 2 copied Gible and Pikachu to blast them off, while it also copied Croagunk to stab Brock for flirting with Nurse Joy.