Greig Pickhaver AM (born 1948?, also known as H.[HARRY]G. Nelson) is an actor, comedian and writer, who forms one half of the Australian sports comedy duo Roy and HG. The award-winning duo originally teamed up in 1986 for the Triple J radio comedy program This Sporting Life, which was broadcast nationwide for 22 years and led to several successful TV spinoffs.
With John Doyle as Rampaging Roy Slaven, they have appeared on television shows such as The Dream with Roy and HG, This Sporting Life, Club Buggery, The Channel Nine Show, Planet Norwich, Win Roy and HG's Money, The Monday Dump, The Nation Dumps, The Dream in Athens and The Memphis Trousers Half Hour. Pickhaver was featured in the SBS series Who Do You Think You Are? in September 2015.
Pickhaver was born in Nuriootpa, South Australia and is a graduate of Flinders University. After a stint as a roadie for Australian rocker Billy Thorpe in the early 1970s, Pickhaver moved into radio broadcasting on 3RRR in Melbourne. This led to acting and comedy, developing the HG Nelson character while performing in the Melbourne radio sports comedy show Punter To Punter in the early 1980s. He met Doyle in 1985 while both were playing minor characters in an SBS TV show and they teamed up as Roy and HG in 1986.
Pickhaver has appeared in many TV programs and advertisements (often as HG Nelson) and starred in the cult Australian comedy film This Won't Hurt a Bit opposite Jacqueline McKenzie. In 2003 he appeared in the political comedy, The Honourable Wally Norman.
- 1989: Pants off, this sporting life, by Roy Slaven and H.G. Nelson
- 1994: Where it all went wrong [sound recording] : address delivered by H.G. Nelson, anti-smoking activist, to the National Press Club, Canberra on World No Tobacco Day, 1 June 1994
- 1994: Boys and balls, by Brian Nankervis; in the press box: Roy Slaven and H.G. Nelson 
- 1996: Petrol, bait, ammo & ice, by H.G. Nelson, with a foreword by Roy Slaven; illustrated by Reg Mombassa
- 1999: It's yours for a sawn-off! : Sameranch's Sydney, by H.G. Nelson; illustrations by James de Vries
- 2006: The really stuffed guide to good food 2006, edited by H.G. Nelson
- 2008: Sprays, by H. G. Nelson 
- 2011: My life in SHORTS, by H. G. Nelson
- "Biographical cuttings on Greig Pickhaver, broadcaster and entertainer". National Library of Australia. Retrieved 2009-04-09.
- National Film and Sound Archive: Sounds of Australia.
- "This Won't Hurt a Bit". Internet Movie Database.
- Nelson, H. G.; Roy Slaven (1989). Pants off, this sporting life. Crows Nest, N.S.W.: ABC Enterprises for Australian Broadcasting Corporation. p. 143. ISBN 0-642-12888-X.
- Nelson, H. G.; Tobacco Interagency Committee of the A.C.T (1994). "Where it all went wrong (sound recording) : address delivered by H.G. Nelson, anti-smoking activist, to the National Press Club, Canberra on World No Tobacco Day, 1 June 1994". 1 digital audio tape (ca. 47 min.). Retrieved 2009-04-09.
- Nankervis, Brian; Slaven, R.; Nelson, H. G. (1994). Boys and balls. St. Leonards, N.S.W.: Allen & Unwin. p. 257. ISBN 1-86373-738-3.
- Nelson, H. G.; Roy Slaven; Reg Mombassa (1996). "Petrol, bait, ammo & ice". Book. Pan Macmillan. p. 220. Retrieved 2009-04-09.
- Nelson, H. G.; James de Vries (1999). "It's yours for a sawn-off! : Sameranch's Sydney". Book. Random House Australia. p. 92. Retrieved 2009-04-09.
- Nelson, H. G., ed. (2005). The really stuffed guide to good food 2006. Sydney: Pan Macmillam Australia. p. 233. ISBN 1-4050-3697-4.
- Nelson, H. G. (2008). Sprays. Sydney: Pan Macmillan Australia. p. 225. ISBN 978-1-4050-3883-6.
- Nelson,H.G., ed. (2011). My life in SHORTS. Sydney: Pan Macmillan Australia. ISBN 9781405039451.