Thanks to Eotyrannus for the inspiration.
Pittraps are a species of carnivorous plant in the phylum pseudoanimalia. They are native to Thanatos and live in swamps. As the name suggests, these plants root into the mud, making a hole. The plant then forms inside, and mud covers the plant, with only the leaves showing above. It uses these leaves to photosynthesize. But this is not it's main method of feeding. When an animal walks into the mud covering the plant, a special appendage stabs the animal in the torso, dissolving it's organs and sucking up the juice. The animals empty corpse then becomes a trap for more animals that the plant eats.
The actual underground portion of the plant looks like a water lily, with a small spike in the middle. Out of each side is a huge leaf that breaks the surface of the mud. When an animal walks over the plant, the spike then becomes much larger, stabbing an animal in the torso.