Health What is a stubborn beast? What is a stubborn beast? 4 letter answer(s) to stubborn beast MULE. What is a duo plus one? 4 letter answer(s) to duo plus one TRIO. a musical composition for three performers. three people considered as a unit. a set of three similar things considered as a unit. three performers or singers who perform together. Related Posts:Is Duo Mobile a spy app?How long did Belle live with the beast?Are there 2 Beauty and the Beast movies?How do money mules work?