Lady Gaga to join Jason Segel’s The Muppets Lady GaGa is rumoued to be making an appearance in the new Muppets movie. Forgetting Sarah Marhshall’s Jason Segel penned the script for The Muppets, which sees Segel take on the lead role of Gary. Amy Adams, Chris Cooper, Zach Galifianakis, Rashida Jones and Kristen Schaal are also said to be among the cast. Gaga famously took Kermit The Frog as her date to the 2009 VMAs; she also wore an outfit made entirely out of Kermits for an interview on German TV. The Muppets will open on Christmas Day 2011.