He was born at Hillingdon County Hospital in Middlesex but he grew up mainly in Coventry. He started ventriloquism at the age of eight and had his first booking aged ten. He worked the clubs and cabaret circuit with his dummies: mainly James Green and Maxwell Monkey, but also Sexy Rexy the Wolf, Puppy Doll the Poodle, Rikki Tikki the Tiger, the Ugly Duckling and Russian Bear. Eventually he began appearing on British television, the first time in 1955. He was also well known in America, with five performances on the Ed Sullivan Show between 1962 and 1964. He appeared on the Royal Variety Performance on 2 November 1964 with a corgi as a dummy and Kenny Baker as a vent dummy which comes to life. 
- "The Call Boy (magazine of The British Music Hall Society)" (PDF). Spring 2011. Retrieved 17 March 2017.
- Free BMD records birth as: Spicer, Dennis G; mother's name: Smith; Registered: Uxbridge Middx; March quarter 1935, vol 3a, page 100 (not 1936 as recorded in IMDb)
- "Royal Command Performance video on Ventriloguist Central". Retrieved 17 March 2017.