I'm not sure but maybe it could be Daria the dark ghost Pokemon or the Pokemon who can change in other Pokemon (Pokemon movie 13) I can`t say the name because the movie 13 starts in June 6 (not sure)
Episode 42, Showdown at Dark City. Ash, Misty and Brock use fake names about 7 minutes into the episode.
POkemon episode Hatching up a plan
Ash Ketchum used the fake name Tom Ato, derived from tomato in the episode "Showdown at Dark City" for safety.
yeah i think there is---------------------------------------------------------------------------------------ANOTHER ANSWERyes there is, at the battle frontier where ash and the gang met the last frontier brain (Brandon) in the Temple and ash got possessed by a evil king.ALSO the 13 Pokemon movie will have dark ash in it.
The name of the episode in which Ash enters the Indigo Pokémon League is "All Fired Up" however his first battle in the Indigo Pokémon League is in the episode which is titled "Round One - Begin!"
The name of the Pokémon episode is "A Shipful of Shivers".
Ash receives his Phanpy as an egg, in the episode, Extreme Pokemon!
You must be talking about the episode where ash and tracey get sick from a poisonous Pokemon and that episode is called the stun spore detour
Ash battled Norman in the episode "Balance of Power."
the second episode.
In the episode Trees a Crowd.
episode 56