That's the walking, talking tree and Marvel superhero Groot telling you the wonderful news: is now streaming. The Marvel film that premiered on May 5 in theaters around the country is available to watch again (or for the first time) on Disney+.Peter Quill and the gang are back in the third installment (or fourth if you count the holiday special) of. As of today, August 2, you can now watch the hit film with a Disney+ account.Part of Phase Five of the Marvel Cinematic Universe (MCU), soared at the box office upon its release in theaters.