Demolition at the bottom of the lake

[You followed the blue-green Flower-Planting Frog back down to the lakebed and found a route that avoided the other poisonous frogs.]

[As you approached the lakebed, you took an antitoxin potion, gaining five minutes of toxin immunity.]

[In a dark corner of the lakebed, you saw a low stone mound jutting up ahead. It was covered in jagged holes, all interconnected, like a hollow ornamental rockery. Each hole was also sealed with a layer of transparent mucus, enclosing the entire rockery like a barrier.]

[This was a nest formed by a species of Deep-Sea Hard-Shelled Snail using its shed shells and congealed mucus. It was extremely sturdy and could prevent other creatures from entering or leaving. Only those covered in the shell of the same species of snail could pass through the membrane and move freely in and out of the rockery. After the hard-shelled snails on the lakebed went extinct, the Flower-Planting Frog tribe occupied the nest and used it as a prison.]

[You swam up to the rockery. Through its dim gaps, you vaguely made out a familiar frog-like figure inside: your Familiar, the Pocket Toad. Countless little tadpoles floated beside the Pocket Toad, circling around him as though begging him for food.]