Wobbuffet Festival crashers
From Bulbapedia, the community-driven Pokémon encyclopedia.
The Wobbu-palooza Festival Crashers are characters of the day in the episode Wobbu-palooza.
They were banished from the Wobbuffet Village, because they used their Pokémon to attack the village in order to build up their strength. One year later, the three boys attacked innocent Wobbuffet during the Wobbuffet Festival. With the unexpected help from Team Rocket, Ash and his friends drove the naughty trio out of the village.