it's in between the two bones in the corner of the room. just dig there and you'll find a secret passage way.
Zino is in the Secret Tunnel.
you can get it from the mole's secret tunnel;]
It's in there somewere in tunnel 4
he's in the moles secret tunnel in rivet ravine
Brachio is in the Secret Tunnel in Rivet Ravine.
moles secret tunnel, in rivet ravine--tunnel #2 or #4 it's most often in the 2nd tunnel.
Megath is in the mole's secret tunnel The mole's secret tunnel is in tunnel 4 You can only access it after you finish the whole game
You can find him at the end of the secret tunnel in Rivet Ravine.
Moles secret tunnel -Noah Fredrick
Go in rivet ravine and you'll see it
In the Mole's secret tunnel after you beat the game
tunnel number 4