Pack a Punch a Gun, go to the alley by the carbine (Gewehr side of the Main Frame).

Peer past the window at the end of the alley, you should see a small box with a glowing dot on it in a six-columned structure (hard to make out structure).

Shoot that box with the PaP'd gun and you will see items fly out and up. A voice will say something like "I want to play a game, how about hide and seek?".

At this point, 2 bears and a monkey will appear around the map, shoot them and the voice says stuff like "You found one" + "You found another one" and the third says "You win, GAME OVER".

Bear 1: Stand on the Main Frame facing PaP and look right and up at a window with flames in it. Bear number 1 holds the Bowie knife.

Bear 2: Looking at the Trenchgun, turn right and you will find a Bear with Juggernog in one of the animal cages. Monkey:
In the furnace under the stairs leading to Teleporter B, difficult to see in the flames.