You will get the chance to either meet Mike or Sulley at the end of your class. Which one you meet will depend entirely on their availability on the day of your visit.
This tour is part of the Star Guest Program for 2013. There is a fee to take part, and places can be limited. Language options might also be limited. For how long this tour will be offered going forward, is unclear.
Check with City Hall on the day of your visit for more information.