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

Stresso is a recurring NPC that is generally seen in various states of distress. At first, they are stressed about the broken elevator on the first floor of the East Mines, and join Clover for an awkward elevator ride once it is fixed. After this, they appear further ahead in the mines with a relaxed expression and thank Clover for their help. Stresso is one of the characters tied down to the right train track during the "Train Problem" mission in the Wild East.

Stresso

That one stressed NPC in mines - Undertale Yellow 