At the Opera

Director: Juan Pablo Zaramella
Writer: Juan Pablo Zaramella
Country: Argentina
Official site

Guard Dog (2004)

Director: Bill Plympton
Writer: Bill Plympton
Country: USA
Awards: ANIMA Special Jury Mention, Toronto World of Comedy International Film Festival Best Animated Short
Guard Dog in IMDb

Robin Hood (1973)

Director: Wolfgang Reitherman
Writer: Larry Clemmons (story), Ken Anderson (character and story conceptions)
Country: USA
Awards: Golden Screen 1976
Robin Hood in IMDb
Official site