Dungeon Online

Hello everyone! In the past week i have been thinking about mini games that you can play with friends on Dungeon Online. Then a friend of mine suggested that we add the Gauntlet. The Gauntlet is a arena where you and 2 other people team up to defeat waves of monsters and bosses. When you finish, you get tokens to by new armor and weapons with. The only thing I'm stuck on is what monsters do I add? Here is the list of monsters that I have programmed in right now, and are programming in:

-Gauntlet Warrior

-Gauntlet Archer

-Gauntlet Magician

-Gauntlet Dragon

-Gauntlet Demon Boss

-Gauntlet Knight

-Gauntlet Reverant

-Gauntlet Snake

I need your ideas on what kind of monsters to add. An suggestions would be appreciated. 

Thank you

-Dungeon Online Team