The military version of the Viking, the Vicker's Valetta, was universally known as The Pig, throughout the RAF.
I always understood that it got its name from its portly dimensions rather than it flying characteristics.
Interesting statistics:
Vikings produced 163
Valetta's produced 263
I do believe that 3 Vikings were bought by the RAF for Queens Flight.
With 160 Varsity's, Vickers probably made a fair profit on the series.