About Mr G

Mr G is a character on Australian mockumentary, Summer Heights High, played by Chris Lilley. Mr G (real name Helen Gregson - which he changed to Greg Gregson) is a drama teacher at the fictional high school Summer heights High, and is known for his unusual teaching methods.
He believes he is a really talented performer and teacher, and that the children at the school all like him. He doesn't get on very well with his colleagues due to his arrogance, self-obsession, and quite nasty nature. He does, however, have a close friendship with science teacher Rodney. Although Rodney is married, there is a question mark over just how close the two of them are.
Mr G likes to write and direct school musicals, with Summer Heights High focusing on one about the drug overdose of a student, Annabel Dixon. When Annabelle's parents read the script and were unhappy about it, he kept the idea but changed it so it focused more on him. He called it "Mr G: The Musical".
Other Mr G musicals include:

Tsunamarama - about the tragedy of the 2004 tsunami, set to the music of Bananarama
You Can't Skate, Mate - based on the song Skater Boi by Avril Lavigne
Ikea: The Musical - about the furniture store, Ikea
Downloading - about a computer that falls in love with its owner

One of the songs, Naughty Girl from Mr G: The Musical was released as a single in Australia, reaching number seven in the Australia ARIA Singles Chart.