Alec: Four eyed Library man

Ashley: Cowgirl

Dan: Purple glasses

Drew: Sweater freckles

Ellie: Carrothead

Fiore: Little Gremlin

Gabby: Hippie girl

Grett: Miss Piggy (After All stars) Goldie

Jake: Blueberry

Lill: Miss Scoutleader

Miriam: Tough Granny

Nick: Moneyman

Tom: Shadow Ninja (All Stars) Scar man

Will: Big buddy

S2

Aiden: Goth bud

Ally: Gamer girl

Connor: Perfume man

Hunter: Mr Nightmare Eyes

James: Camera guy

Kai: Weed man

Karol: Ms Bossy lady

Lake: Bookworm

Maggy: Red braids

Oliver: Blue Hood/Intern guy

Riya: Actress lady

Rosa Maria: Violet streaks

Tess: Lady Noir

Yul: Mushroom Fetus Hoe

Staff:

Kristal: Hostess lady

Marcus: Mr Puppet driver

Nina: Satan Puppet

Derek: Blackberry

Trevor: Giraffe

Emily: Lady Drama

Jensen: Criminal Driver

This is how River would refer to everyone in the DC cast. Unless he REALLY trusts them or he Likes them, This is the nicknames he uses for them. (River has a habit of calling people nicknames, but don't worry. He isn't racist or bigoted like Yul.)