(Note: That the song above him is his theme song)

Doug

Team:

Grimer (15): Mud Slap, Disable, Poison Gas, Sludge

Junkeon (15): Smokescreen, Poison sting, take down, absorb

Stunky (15): Fury Swipes, Poison Gas, Theif, Rest

Lilkill (15): Lick, Fake Tears, Bite, Sludge

Trubbish (15): Toxic Spikes, Acid Spray, Amnesia, Sand Attack

Roadskim (18): Toxic, Protect, Poison Fang, Metal Claw

Rewards for beating him: The Trash Charm, TM for Toxic, Poison Barb, some ingredients, and his number.

With his number, you could call him to give your pokemon a pokejob to basically clean up the wild area and such. Also you can go back to his gym and get random items or maybe a Lilkill for yourself.