Final answer:
In the novel 'Life of Pi,' during a stare down between Pi and the tiger Richard Parker, a rat appears.
Step-by-step explanation:
In the context wherein Richard Parker and Pi are having a stare down, the small animal that appears is a rat. This scenario occurs in Yann Martel's novel Life of Pi, where the protagonist, Pi, is stranded in a lifeboat in the Pacific Ocean with a Bengal tiger named Richard Parker. The sudden appearance of the rat adds tension to the scene, illustrating the struggles of survival Pi faces and the range of life present even in the confined space of the lifeboat.