Add a soda slug.

I think this would be a massive improvement to the game in many ways. A waterslug relative that has flavored carbonated water in it, rather than regular fresh water.
Maybe the explanation for the creature’s odd and amazing trait is the slug is in a symbiotic relationship with an algae, which produce sugars and then release them into the waterslug’s mini-biosphere thing, and then there’s carbon that gets in there somehow to stop any bacterial growth or anything trying to infect the slug to get to the sugar.