A clip show is an episode of a particular series that is mostly made up of short segments from previous episodes, often to highlight what has happened during the series.
Prime time clip shows
In 1997 through 1999, 3 clip-shows were planned for Pokémon. Only two of those have aired, with the third one being cancelled due to the Porygon incident. Those clip-shows were hour-and-a-half to two-hour-long installments, aired after the regular Pokémon episode of the week in Japan. Much like Pocket Monsters Encore, the Weekly Pokémon Broadcasting Station, Pokémon Sunday and Pokémon Smash, they haven't been aired outside of Japan.
Pocket Monsters, Fall Special
|October, 10 1997||Hour-and-a-half special, aired right after EP028||To sum up episodes up to EP027|
Pocket Monsters, Winter Special
|Unaired||Planned to air right after Snow Way Out! but eventually cancelled during the actual airing, as it aired out of order||To sum up the episodes until Holiday Hi-Jynx|
It's the New Year! Pocket Monsters Special
|January 1, 1999||2-hour special, aired right after EP077||Ash has qualified for the final competition of the Pokémon League.|
Regular broadcasting clip-shows
Those clip shows have been released typically as the second episode of a one-hour special in Japan (though AG120 stood alone). They have been used to recap what has happened up to a certain point in the anime's current series.
|EP040|| おおみそうかだよ！ ポケットモンスターアンコール
It's New Year's Eve! Pocket Monsters Encore
|Unaired||New Year special, planned to air on December 31, 1997, but eventually cancelled following the 1997 Porygon incident.||Content unknown|
Satoshi and Haruka! Heated Battles of Houen!!
|March 24, 2005||As Ash and friends approach Slateport City, site of Hoenn's Grand Festival, Ash remembers his Gym battles in the Hoenn region, while May remembers her Contest competitions.||Both Ash and May are about to compete in their regional goal, the Pokémon League and Grand Festival, respectively.|
Satoshi and Hikari! Facing a New Adventure!!
|September 27, 2007||On their way to Hearthome City, Ash, Dawn, and Brock recall their adventures together so far.||Summarizes the first year of the Diamond & Pearl series.|
The Mysterious Creatures, Pocket Monsters!
|March 26, 2009||The gang travels toward Snowpoint City, and along the way, remember what has happened so far in their adventure. Future events are also hinted towards...||Summarizes the Diamond & Pearl series so far, hints at near-future events including the reappearance of one of the Frontier Brains of the Kanto Battle Frontier.|