New Info?] Looks like Party Hat Gengar will be able to Mega Evolve : r/TheSilphRoad

Pokemon GO Halloween COUNTDOWN: Event news LEAKED, Gen 3 confirmed, when does update start - Daily Star

MEGA EVOLVING Lucky Shiny Party-hat Gengar!!!

Halloween 2020, Pokémon GO Wiki

Does Mega Gengar Keep His Costume? : r/pokemongo

Gengar, Pokémon GO Wiki

How to dress up your Pokemon on Pokemon go? Or is it only on Pokemon lets go - Quora

Mega Evolution PVE Tier List : r/TheSilphRoad

Play Pokémon Go Like a Pro with These Companion Apps for iPhone and Android Phones « Smartphones :: Gadget Hacks

MEGA GENGAR RAID in Pokemon Go - Halloween 2020 Costume Gengar

New Info?] Looks like Party Hat Gengar will be able to Mega Evolve : r/ TheSilphRoad

New Info - Mega Gengar added to the Game Master : r/TheSilphRoad

Well that's new. Mega Gengar is not displaying properly when trying to take a buddy photo. it's some sort of 2D negative image. : r/TheSilphRoad

Do they lose their costumes if mega evolved? Gengar might just be worth it… : r/pokemongo

Gengar, Pokémon GO Wiki