How do I add a Disney figure as a boss in a created level?

I'm new to infinity and have seen multiple custom made vs battles on YouTube. Example someone added spider man to their playset and was fighting him one on one. How do I go about doing that with other characters?

You can use the boss fight generator to fight villain figures but you can't fight other figures like Spider-Man. They were probably fighting another player.

Weird it wasn't split screen though like when two people are playing.

@MarvelWarrior could have been two players online therefore not requiring split screen. Would have to see it to know.

An shoot forgot about the online option here's the link

[Sheriff Woody]

that is 2 player online, on occasion you can see the second player has a 2 above their character