Hawkins joined the Royal Navy, entertaining with impressions for which he wrote scripts, and survived when HMS Limbourne sank after being torpedoed escorting the cruiser Charybdis near Guernsey.

He was rescued by Ronnie Hill, a theatre actor at the time, and while recovering, Hawkins took part in plays, which resulted in his being taken into Combined Operations' Entertainments productions of the Royal Naval Barracks' Scran Bag.

[1] Following his time with Scran Bag, Hawkins won a two-year place at the Central School of Speech and Drama,[1] and in 1949, his television career began with an adaptation of J.B. Priestley's The Good Companions.

[2] He began his long association with children's television with the magazine programme Whirligig voicing several characters, including Mr. Turnip, Alexander Scrope, Petrio in Stranger from Space, Albert in Jeremy Make-Believe and the Can We Help You?

[4] The scripts would be written in English, and Peter would translate them into Oddle-Poddle,[5] creating words similar to "Slogalog" (Slowcoach the Tortoise) and "Haddap" (Hello).

Creator John Ryan praised him for his ability to perform many different voices,[10] although he had to be hidden behind a monitor due to his facial expressions distracting the animators.

Despite his son Silas being a Doctor Who fan, he did not find it strange that it was his father voicing the Daleks, although the Daily Express framed it as if he boasted to his friends about it, which Hawkins hated.

[17] Throughout the 1980s, as well as providing voices in SuperTed, The Family-Ness and Jimbo and the Jet-Set, Hawkins reprised his roles of Bill and Ben for various shows, including Six Fifty-Five Special and Blue Peter.

Due to Hawkins' role as Spotty Dog in The Woodentops, he was chosen by Nick Park to voice Gromit in his short film A Grand Day Out.

[19] He eventually decided to make Gromit a mute character to save on the effort required to animate his mouth, instead using his eyes and monobrow to communicate.

[1] In 1977, however, he sold his collection of sword guards at Sotheby's, with the highest-selling, by Seiyoken Hagiya Katsuhira and depicting the Three Sake Tasters, fetching £4,200, an auction record.

Despite his busy schedule, Hawkins spent lots of time with his son, reading bedtime stories as if he was recording, which Silas thought was overwhelming.

A showing of "The Survivors", his first Doctor Who episode, was arranged, and Silas scattered his ashes at Fermain Bay, Guernsey, where HMS Limbourne sank.