He once notoriously referred to New Zealand as 'a poxy little island in the South Pacific', posted a referee's jersey to then injured Wales wing Mark Jones in an attempt to taunt him back to fitness and regularly goaded the media with an array of T-shirts, which he unveiled in dumbstruck manner instead of answering 'obvious' questions.
Such was his popularity in Wales, where his matchday role as water carrier often saw him moonlight as cheerleader, that one section of fans took to wearing Jonno masks.
Yet with the two-Test Bundaberg Rum Rugby Series, which pits him against his former colleagues, just weeks away, Johnson has stopped short of getting up to his old tricks and reverted to the time-honoured tradition of talking up the opposition - for now.
"Welsh rugby has greatly increased in depth in recent years and the team they are bringing out is brimming with international experience and are highly suited to Test rugby," said Johnson.
"The 18 players they have left at home were all part of the Welsh team that finished equal bottom of this year's Six Nations, so I don't think the new players coming in can be regarded as second choice.
"Based on the number of changes, I think the Welsh coaching staff will use these matches to draw out their best 30 and will be testing as many players as they can before the World Cup."
Wales play the Qantas Wallabies at Telstra Stadium on May 26th before moving north to the Suncorp Stadium. The two sides played out a nail-biting 29-29 draw in November's Millennium Stadium clash the last time the two met. Now both will be looking to inflict a psychological blow before their crucial Rugby World Cup pool match in September.
Johnson insists the inclusion of six British & Irish Lions players - Gareth Thomas (Captain), Gavin Henson, Gareth Cooper, Brent Cockbain, Michael Owen and Dafydd James - will add invaluable experience and resolve to the Welsh outfit.
"Six of this squad has played with the British & Irish Lions and they will chomping at the bit to have a crack at the Wallabies," he said. "They know a good tour in Australia will put them into a strong position to be in the squad in France.
"This touring forward pack will have more experience and be more abrasive than their Six Nations counterparts. Come World Cup, there's a good chance that there will be many players from this tour in their squad in France."