spin-off

noun

• An offshoot.
• An incidental benefit or unexpected pay-off.

  "Space research often provides a spin-off for everyday technology."

• By-product.
• A fictional work where the protagonist was introduced in a preceding work or at least shares the same setting, often in a different aspect.

  ""Frasier" was a spin-off from the sitcom "Cheers"."

• The formation of a subsidiary company that continues the operations of part of the parent company; the company so formed.