Where to catch, #0044
Gloom in Diamond and Pearl: 3 places, levels 50 to 53
4 encounters by area
Places
Route 224, Route 229 and Sea Route 230
Other games
Also found in 14 other games
Red and Green (Japan)Red and BlueYellowGold and SilverCrystalRuby and SapphireEmeraldFireRed and LeafGreenPlatinumHeartGold and SoulSilverX and YLet's Go, Pikachu and EeveeSword and ShieldThe Crown Tundra