Krishna's victory over the snake demon Agha

Krishna's friends, believing they are entering a cave, unknowingly step into the mouth of the demon Agha, shown twice in this painting.

The demon lay down on the way with a view to devouring them with an expanded mouth like the cave of a mountain. The lower lip extended to the earth and the upper touched the clouds and the ends were like expanded mountain caves. The teeth were like the summits of a mountain; the interior of its mouth was like darkness and the tongue was the road thereof. Krishna, thinking how the life of this wicked one may be taken and those of the boys saved, himself at last entered into the mouth of that demon. Being desirous of destroying it, he speedily increased his own form in the throat of Agha. Thereupon the throat of that huge-bodied demon was obstructed and his eyes burst out of their sockets. The wind inside his body was obstructed and being choked in full in no time it issued out riving the head of the demon.
 From the Bhagavata Purana