He knows it, sees it. Plate face with eyes straining out of it; meaty mouth erupting like a nodule to habitually laugh. It's lost in the darkness at the edge of the cavern. It's teeth clap together but they never clack or clatter. Why do they never speak?
Although, it's clearly half dead. Some spawned abomination. Torn up somehow and left for dead. Instead of death however the creatures head has become fused upon a mushroom and now lives an insane twilight existence deep in a throwaway cavern. Sometimes, for periods, its eyes seem to bleed some subhuman consternation at its new lot, but the laughter continues.
He doesn't kill it.

Elegiac confirmed bought laced weed