Doctor Strange: 31 Easter Eggs & References You Must See

In the mid credits sequence, Thor is seen conversing in the New York Sanctum with Thor (on dress down Friday by the look of him). The pair verbally spar a little, Strange conjures his Asgardian guest some beer and they get to business.

Ironically, Strange reveals that he has a powers watchlist, which tracks any entity deemed a mystical threat to Earth - ironic since he was on SHIELD's watchlist as a threat to Earth too. His list includes Loki, who has pinged the list after reappearing in London with Thor.

Presumably since Thor is now aware that his brother is alive (both are looking for their missing father), this is a scene picked out of the middle of Thor: Ragnarok, just as the post-credits stinger on Ant-Man was a scene taken from Civil War. So that's confirmation that Strange is appearing in Ragnarok then.