Change your preferences here.
Transforms into the target, copying its stats (except HP), moves (at 5 PP each), type, and stat modifiers. This move is not affected by accuracy or evasion modifiers. Any stat modifiers currently on the user are negated after using Transform. The level of the user remains the same, thus if the user is a lower level then the Pokémon it copied, then its attacks will not deal as much damage, despite all of the stat changes.
Transform is terribly gimmicky and useless. Mew has better options and Ditto is too slow and frail to put it to a good use.