Zoey

Marie

Ignacio

Galen

Ollie

Tala

Quinn

Bodie

Teacher

British

Vampire Bodyguard

Francis

Woman

Bodyguard

The Narrator

African lady

Soft Bubbly

Southern

Robot

Hailey

French

Hood

Indian Girl Accent

A French Girl

Male Russian Accent

Irish

Billy appears to be the original Billy (bruh) or ULB-278. It appears to replace A-278. When Billy spawns, he opens a blue portal instead of purple one. According to this page here Billy appears to be saying, "Hi, I am Billy from the hit game Interminable Rooms, yayayayayayay!". He will then go back to past rooms to despawn and begin spawning more Billys.

Billy or ULB-278

billy