Incubarana and Salivantulas

Incubarana (Incubatorana) are a genus of frog found in the amazon rainforest as well as the south American savannah. They are descended from the Chiasmocleis albopunctata frog. Their body is a motley of greens and browns in order to blend in with the riverbank. As adults, they come in at a foot long with an incredibly large mouth. 

Insects, namely large insects and large water ants, are the main prey items of the Incubarana. The only issue is that they are ambush predators and rarely ever move. They are also too large to move without notice, so instead they have their prey brought to them. Their personal delivery man is a tarantula know as the Salivantula.

Salivantulas (Orearanea orearanea) are a monospecific genus of tarantula. They come in at 5 inches in length and are dark brown. They live within the large mouth of the Incubarana. In order to not sting their home, they possess no stinging hairs. Instead, they have extremely potent and quick acting venom. 

When the frog has no prey passing by or the spider needs to feed, the frog will let the spider out and let it eat or bring food back. If the spider doesn't uphold it's end of the deal, it will get eaten and maybe bite the frog in the process, taking out both of them. In the case of predators finding the frog, the frog will unleash the spider to protect the both of them.

Since Salivantulas don't burrow, they do it outside of the frog which is obviously very dangerous. If they put their eggs in the frog's mouth, its casing will dissolve in the saliva. Instead, they will carry the egg sac around on their backs.

For the Incuburana, they have a massive mating meetup in a slow part of the river. Once the females lay the eggs, they store them in their mouths to keep them away from the dangerous waters. Since they can't eat with eggs in their mouth, their spider companion gets all the food for them, liquifies it and practically pours it down their throat.