Bill Wiggins first appeared in "His Last Vow", where he was guarding the drug den Sherlock was in. 'Billy', as he is also known, is shown having keen powers of deduction. He is able to deduce the fact that John Watson is cycling to work simply by judging the state of his shirt. Later he creates a compound used to drug the whole Holmes family, together with Mary, on Sherlock's request.
Bill begins residing with Sherlock at Baker Street, in which Sherlock has seemingly gone completely over the edge and locked himself away after John refused to see him following the death of Mary, a death which John accused Sherlock of being responsible for. Bill ended up vacating the premises as he felt that Sherlock had finally lost the plot.
- Bill Wiggins is based on the canon character Wiggins, one of the Baker Street Irregulars who helped Holmes during multiple cases.