People turn to animals when describing Boris Johnson. To his aides, the former prime minister was “Big Dog”. One commentator labelled him a “giant toad”, squatting over British politics. Another said he was a “bulletproof Gunnersaurus”, after Arsenal’s dinosaur mascot. When rumour emerged that Mr Johnson was considering a return to front-line politics, the menagerie expanded. “The big, blond-maned cat is stalking the leader of the Tory party,” said one commentator, panting.