take a loo
Before chapter 363 when the face of Pain has actually been fully shown, there was a theory highly popular in fandom that stated the Akatsuki Leader is the Fourth Hokage. This speculation has been recently resolved as incorrect, however even in the light, Pain's Yahiko body resembles Minato Namikaze in ways. Some fans still believe Pain is the Fourth Hokage in disguise as not to have people know who he is since Pain has multiple bodies, but this fact has yet to be proven or disproved. Another speculation is that the multiple bodies of Pain are a variant of his Shapeshifting Technique, used to split his chakra and abilities into multiple bodies.
It can also be inferred that Pain has a seventh body, because in the message Jiraiya left, it mentions that "the real one is not with them". This could mean that the head body, which could be Nagato, controls his six bodies from a distance, and as long as the seventh one survives, Pain can't die.
If you look closely at the piercings of the Pain bodies faces you can see: first body has seven piercings in both ears and six piercings in his nose (if you think it over there are only three piercing in the nose), second body has seven circle piercings on his face, third has body six circle piercings on his face, fourth body has six piercings under his lips, fifth has body six piercings on top of his head, sixth body has seven circle piercings on his face, seventh body has seven piercings on his face. This seems to be connected with the six/seven theme with Pain. Whether it is a clue to how the bodies work or not is unknown.
The piercings in Pain's bodies also appear to correspond with the abilities of each body. For example, Pain's fifth body has five spikes protruding from his head, while it is seen in the manga that his head opens up as part of a technique. Pain's first body also has piercings near the mouth and ears. The person controlling Pain may have pierced the body there so he could communicate through the Deva path