noun spin-off (from / of sth)
1.
an unexpected but useful result of an activity that is designed to produce sth else :
commercial spin-offs from medical research
2.
a book, a film / movie, a television programme, or an object that is based on a book, film / movie or television series that has been very successful :
The TV comedy series is a spin-off of the original movie.
spin-off merchandise from the latest Disney movie