Volga:
In the Terminal within the room where you kill the Tsarfish.
At the back of the room (oposite the overlook of the hanger) hanging on the boat with the fish inside it, is the toy.
Caspian:
At the cave system, juat before you go up to get the water for the Aurora' tank.
On the left as you go passed Damir's camp outside tge cave system is a boat with several dead bodies surounding it. On a pole down this drop just infront of the boat, is the toy. (DO NOT CROSS THE BOAT, it's on a pole before then)
Taiga:
Go through the mission as normal, causing as little or as much havok as you please. When you get to the Admiral's room at the end of the mission, just behind him is his map hung up on a board.
The toy is hanging up at the board.