I used this picture as a reference for the callouts: http://i.imgur.com/70ySTtP.jpg
Bananagaming: In a flowerpot on top of the small wall next to CT Stairs leading to A

Kandis: Behind the door next to the "button" on boost spot on A Long

Launder: Under a cannon on A

Mantrousse: In the concrete mixer in T Halls

TheWarOwl: In left corner coming out of Power Box/Dropper into B

Nickbunyun: On the platform with the floodlights in Upper Halls (normally not reachable, you have to jump from the top of the stairs onto the broken pillar in front of the floodlight)

MojoOnPC: In the chicken hut in the back of B

Trilluxe: Where you spawn

TheGregster101: Behind the hay bale on top of the wooden platform by Bypass (look in the image for the callout; jump on top of the stack of barrels to get on top of the platform)

Anomaly: Under the 2nd wooden platform in T Spawn

3Kliksphilip: Between the wooden crates and the small wall on Terrace (you can see it when going B Long from T side)

Houngoungagne: In a bush near the Spawn (when getting out of the lower end of Snake turn right two times)

Tweeday: On top of the small wooden pillar seen right in front of you when entering Tower/Nest using the stairs (on the hight of the power box)

Sparkles: Under the bench in Connector

Fart Master: Behind the wooden crates in Vent