Indeed, 't was an episode devoted to Robin Hood.
Lynn played Maid Marian. Kermit was Robin Hood, with Fozzie as Little John by his side, Scooter as Alan A'Dale narrating the story with his lute and staging the show, and a whole bunch of other Whatnots as Merry Men.
Gonzo played the Sherriff of Nottingham, and his soldiers were pigs (plus Sweetums). Piggy, who really wanted to play Maid Marian, gets the role of Sister Tuck - and she locks Lynn in her dressing room out of jealousy.
There's also cameo appearances by Lew Zealand, Swedish Chef, Beaker (Merry Men), Lewis Kazagger (sportscaster for Archery Contest), Newsman (townscrier) and Beauregard (jester).
There's an opening scene where the Merry Men "cavort" in the woods. The dungeon scene where Gonzo tortures himself instead of Lynn and gets stretched like in Muppet Treasure Island. The Archery Contest, where Kermit (in disguise) splits Black Bart's arrow in two. A duet with Kermit and Lynn, interrupted by Piggy who lets the soldier pigs lock Lynn in her dressing room.
And the final scene, where the Merry Men plan to release Maid Marian from the castle, but find Piggy there. They leave her tied (with Gonzo cuddling close to her) and release Lynn from the dressing room instead.