In July 2012 McMahon was included in the New Faces of the Just For Laughs festival in Montreal. He has worked in both Canada and the United States as a comedian. One of his comedic personae was Clarence Two Toes, "a Half Ojibway-Half Metis guy that struggles everyday on whether to listen to the 'brown guy' or the 'not quite brown guy' that lives in his head. Clarence Two Toes was featured on McMahon's 2011 album, Live in Red Lake, which he made available on Bandcamp on a pay-what-you-want basis. In 2012 he became the first Indigenous comedian to record a one-hour comedy special, UnReserved, for the Canadian Broadcasting Corporation. He has since done other specials for the CBC, including Colonization Road, in which he travels across Ontario to expose the history of colonial settlement and Indigenous dispossession.The program won the Yorkton Film Festival’s Golden Sheaf Award for Best Documentary – Historical/Biography, and was nominated for a 2018 Canadian Screen Award. In 2018, McMahon published his first book of short stories, The Great NDN Paradox, with Arsenal Pulp Press.
Podcasting
McMahon has been podcasting since 2008. His most popular show, Red Man Laughing, uses humor to tackle such subjects as settler colonialism and racism; it included a season devoted entirely to the topic of Canadian reconciliation. To sustain Red Man Laughing, which draws as many as 10,000 listeners, McMahon has worked toward a mixed subscriber and free-listener model. Interested in the affordability and grassroots appeal of podcasting, McMahon founded an Indigenous multimedia network, Indian and Cowboy. In its first year the network had hosted seven podcasts, including Metis in Space, featuring two Metis women discussing sci-fi; an Indigenous sports podcast called Indigenous Prime; and Think Indigenous,about Indigenous education. In 2016, McMahon expanded his projects into Makoons Media, a multimedia company that aims to create content by and for Indigenous people worldwide. Additionally, McMahon has hosted podcasts for the media platformCanadaland. He hosted Thunder Bay, based on Toronto Star reporter Tanya Talaga's award-winning book Seven Fallen Feathers: Racism, Death and Hard Truths in a Northern City, which investigated the deaths of seven Indigenous youths in Thunder Bay, Ontario. McMahon was also a writer and co-host of Canadaland's political podcast, The Commons.
Activism
McMahon has become increasingly outspoken about anti-Indigenous racism and violence in Canada, and has received increasing attention for his views. Researchers at the University of British Columbia who analyzed Twitter discussions of the Idle No More movement found that, at its peak, McMahon was the tenth most-retweeted celebrity, making him a powerful cultural influencer. Since 2015 he has been an occasional columnist for Vice magazine, writing about Canadian-First Nations politics. In 2017 he publicly refused to attend celebrations of Canada's sesquicentennial.