In search of ideas for cool "snake" sensory play recipes I remembered this recipe with cornflour (cornstarch) and liquid soap, I used a cheap hand wash but I'm pretty sure shampoo or bubble bath will work too and you could use scent to relate to theme etc.
It's an amazing consistency a lot more solid than cornflour and water but can also go more liquid when you warm in hands and hold like bottom right picture or pull between two hands (kind of bubble gum ish)
As with the above dough I'd suggest just keep adding the liquid until it's an appropriate texture.