Oscar host Seth MacFarlane speaks on stage at the 85th Academy Awards in Hollywood, California, February 24, 2013. REUTERS/Mario Anzuoni

Oscar host Billy Crystal talks on stage at the 84th Academy Awards in Hollywood, California, February 26, 2012. REUTERS/Gary Hershorn

Host Jon Stewart delivers his monologue at the start of the 80th annual Academy Awards, the Oscars in Hollywood February 24, 2008. REUTERS/Gary Hershorn

Host Hugh Jackman performs his opening monologue during the 81st Academy Awards in Hollywood, California February 22, 2009. REUTERS/Gary Hershorn

Co-hosts Anne Hathaway (L) and James Franco perform during the 83rd Academy Awards in Hollywood, California, February 27, 2011. REUTERS/Gary Hershorn

Steve Martin performs his monologue at the start of the 73rd annual Academy Awards in Los Angeles as shown in this file image from March 25, 2001. Martin has been selected to host the 75th Academy Award show March 23, 2003. REUTERS/Gary Hershorn FSP - RTRDJS0

Host Ellen Degeneres takes a group picture at the 86th Academy Awards in Hollywood, California March 2, 2014. REUTERS/Lucy Nicholson

Billy Crystal hosted in 2004. Best Picture winner: The Lord of the Rings: The Return of the King. REUTERS/Gary Hershorn

Steve Martin (L) and Alec Baldwin host the 82nd Academy Awards in Hollywood, March 7, 2010. REUTERS/Brian Snyder

Oscars host Chris Rock (C) delivers a joke about PricewaterhouseCoopers, the agency that handled the balloting, at the 77th annual Academy Awards in Hollywood, February 27, 2005. REUTERS/Gary Hershorn REUTERS MM - RTRON41

Host Ellen DeGeneres performs at the at the 79th Annual Academy Awards in Hollywood, California, February 25, 2007. REUTERS/Gary Hershorn

Host Chris Rock opens the show at the 88th Academy Awards in Hollywood, California February 28, 2016. REUTERS/Mario Anzuoni - RTS8FYE