Yes and no. There are tons of party entertainment companies out there that offer all sorts of popular characters. You can have superheroes, princesses, and more to delight your kids’ birthday guests. But because of copyright rules, you won’t find Mickey Mouse any more than you would find Captain America or Elsa. But you will find Mouse Friend, Snow Queen, and similar names. So, yes, you can have a character bearing a very strong resemblance to Mickey come to the party; they just won’t tell you they’re Mickey Mouse.