Pumpkin Rapper was sent down when the Rangers were in a game show. Evil pumpkin seeds were grown in a rotten pumpkin patch to suffocate the rangers. He mostly rapped and he drained the Rangers' energy by wrapping vines around them. He was destroyed by the Power Blaster. He was resurrected the next Halloween by Lord Zedd and was hard to defeat but finally was destroyed by the Thunder Megazord.
Note: also, a history of halloween monster called Pumpkin Rapper to during MMPR classic halloween episode in made by during "Trick or Treat" and "Zedd's Monster Mash" on Zyu2.