Do some training.

You abscond to the forest sneaking past blue knowing how bad the little creep wants to **** you. You look over the pokedex for this ditto specifically trying to learn what it already knows and how you need to train it.

Champ

species Ditto

moves

Transform: The ditto's most basic move, this ditto knows how to use it to transform into the following, Eevee, charmander, squirtle, bulbasaur, pikachu, ratata, spearow, pidgy, and ponyeta. It can use many of their moves instinctively but only moves that could be used by an instance it has used "study" on

Study: allows ditto to "transform" into the studies pokemon later. Using it on new instances of a pokemon may allow it to learn more of their moves.

Whip attack: unlike most dittos this one has learned how to use it's shapeshifting offensively in its native form.

Shell: Uses its shapeshifting to form a hard barrier, improves defense and allows it to shield others.

You are excited and practice its basic moves for a little while then check its moves in the various forms, nothing spectacular but a useful array of abilities and the ponyeta can carry you on its back which is a lot of fun even if you have to be real careful not to get burned.