He is also called things like Tonton, Rekenton, or Nonk.

A very large shark, with a "monster" heart/identity Doesn't hold a card.

He is Erzulie's friend, who raised Agwe. He later dies by Oton.

Reken is shark, while “Tonton” and “Nonk” both mean uncle.

Reken does not have a human-like identity, thus did not have a name-name that stuck. But because of his association with Erzulie, he was seen fondly by siren and humans alike causing the “uncle” part. Ton Reken stuck easily.

Ton Reken had eaten the corpse of Oton, only to unfortunately be consumed right back. His heart was taken use/over by Oton, thus he is either deemed to be dead, or merged with Oton.