Animal Path

The Animal Path (畜生道, Chikushōdō) grants a Rinnegan user the ability to summon a variety of animals and creatures to aid them in battle.

These creatures appear to be immortal, as they could be summoned again after being killed. Notably, summoning creatures through the Animal Path requires neither a blood sacrifice nor hand seals. The Animal Path can also summon people with hand signs, as in the case of Nagato's Paths and Konan. Tactically, the Animal Path's main role in battle appears to be overwhelming multiple opponents with a mass of summons.

In Nagato's case — channelling the Animal Path first through a Fūma clan shinobi and then, for the rest of its service, through Ajisai's corpse — the summoned creatures also appear to have chakra receivers embedded in their bodies, just like the Pain Paths. Nagato also tends to send the Animal Path into battle first, to confuse enemies about how many opponents they truly face. As these creatures display the Rinnegan as well, they serve as extensions of Nagato. During the Fourth Shinobi World War, Nagato used its summons for transport before being reanimated in a form that could move under its own power.

Influences

Buddhists believe that animals live in a different dimension separated from humans not spatially but mentally — called the "Tiryagyoni realm" — an unhappy plane of rebirth built on fear, instinct and survival of the strongest, suffered by animals who serve humans and are, above all, unaware of what befalls them.