Kakuzu, an Akatsuki member who works with Hidan as a pair, has a unique ability. His body is full of black strings that he can use to steal the organs of his opponents.
He uses this ability in order to
steal his enemies' hearts, which gives him two important advantages:
1) Provides a type of "immortality". He can have a maximum of 4 hearts but this means he needs to be killed 4 times without him replacing the lost hearts in the mean time.
2) Allows him to use the chakra nature elements of the stolen hearts. For example, if he steals a heart from someone who possessed the wind chakra nature element, he'd be able to use that.
Is it known what Kakuzu's own original chakra nature element was?