Spider has adapted to life on Pandora, but he is not from Nami, he is human. After Jack and Miles Kucher fought at the bottom of the sea, he chose to save Miles (his father). There are many family dynamics in Avatar 2. Several children of Jack's family demonstrated these developments. James Cameron also said that family is one of the main themes of Avatar 2. Spider and Jack's family obviously have problems. Especially since he was almost killed by his foster mother. Although Spider and Miles seem hostile, he still stays around, which shows that he is eager to have the image of a father in his life.