Marvel Studios has recently brought out a new TV spot for Doctor Strange in the Multiverse of Madness. This promo reveals a new look of multiple cameos.
This is a scene where Captain Carter is about to engage in a fight with Wanda Maximoff. Fans are convinced they have spotted a Fantastic Four member.

There appears to be a blue and black substance on the floor near Captain Carter.
The character Mister Fantastic, has an ability where he can change into a semi-solid liquid state, at his own will. This could be what is being seen here, or maybe this is thick oil from the Ultron bots.
Who could be playing Mister Fantastic?

The rumours are that it is either Ioan Gruffudd, Miles Teller or John Krasinski. Who is your pick to play Mister Fantastic? If the character is in the movie.
Tv Spot
Doctor Strange in the Multiverse of Madness releases in cinemas on May 6.