Complex sentence: Dronkeys were introduced in "Shrek 2" as little more than a stinger gag, as well as for the appeasement of audience members who missed having Dragon in the film, as was revealed to the filmmakers during test screenings.
Split into simpler sentences: Dronkeys were introduced in "Shrek 2" as little more than a stinger gag. Audience members missed having Dragon in the film, which was revealed to the filmmakers during test screenings.