So you take a sickly green ogre, throw in his almost best friend - a donkey - add an evil king wannabe and top it off with a damsel in distress, and you've got the makings of something kids and adults alike can enjoy. If you then add some cute songs, good choreography and incredible costumes, what you'd end up with is the First Stage production of "Shrek the Musical," which opened Friday night at the Todd Wehr Theater.