I have 3 of the 4 monkeys. I have not found one that was listed in the snake holding areas. Ive been underwater and one passage leads to the slime creature which i killed and after 20 tries wiggled through that tunnel to the chest.
I went the other way which only seemed to go to the other room that leads underwater.
Where is that monkey
i have the kitchen monkey figurine and the monkey i chased that gave me a figurine. I also have a thrird one(cant reemeber where i got it)

1. Figurine in a chest in the first entry area down below. Chest may be in shadows a bit,
2. *Snake Figurine, past the Filth.
3. Figurine above the kitchen.
4. Running monkey's figurine.
5. Doors with slots figurine. (5th door)

If you can't get it there's workarounds for 1. Snake Figurine and 2. Missing Monkey Figurine. Tell me if you need one, but I do hope you can find that missing statue!

I need to run through that area again to refresh. Try the right exit, facing the Snake Head. There's some red lines along the walls which are a giveaway you are heading the right direction.

i got there last night right after i left the message for you

I believe the switch combination before you enter the gold coin is 1,3,4