A remarkable man with fiery red hair and a gargantuan appetite for whisky and tall tales, William Dunlop was born in 1792 in Greenock, Scotland, the son of a local banker. He studied medicine in Glasgow and London, and was appointed assistant surgeon to the 89th Foot Regiment in 1813. The regiment was posted to Upper Canada during the War of 1812 in time to participate in the battles of Crysler's Farm and Lundy's Lane. In 1815, he heard that the war had ended while he was in charge of the construction of the Penetanguishene Road. After going on half-pay in 1817, he went to India, attempting to clear tigers from Sagar Island and earning himself the nickname "Tiger". From 1820 to 1825, Dunlop flitted from project to project, writing articles for magazines, giving lectures on medical jurisprudence, and editing newspapers.

In 1825, John Galt of the Canada Company appointed Dunlop Warden of the Woods and Forests, his job being to inspect the company lands to protect them for being spoiled and to select land that could be sold quickly for funds. He arrived in Upper Canada in 1826 and from then acted as second-in-command to Galt. He was present at the founding of Guelph, cut a road to Goderich, and built his home just north of Goderich. When Galt resigned in 1829, Dunlop managed to keep his job. In 1833, he was appointed general superintendent of the Huron Tract. In the same year, he published Statistical Sketches of Upper Canada, an interesting and amusing book that attempted to lure clever young people to Canada.

In 1833, he was joined in Canada by his brother Robert, a retired naval captain and much quieter personality. During the rebellion in 1837, Dunlop raised a military unit nicknamed The Bloody Useless. He commandeered supplies and food from Canada Company stores, leading Galt's successor, Thomas Jones, to demand his withdrawal from militia activities. Dunlop refused and resigned from the company in 1838.

There is a story about the Dunlop brothers that involves Robert's marriage. They had a live-in housekeeper, Louisa McColl, for some years and apparently this had been the subject of gossip that was causing a great deal of distress to her. To end the speculation and to keep Louisa, the brothers proposed that one should marry her. Tiger tossed a coin and Robert lost, mainly because the coin had two heads. So Robert had to propose to her. She accepted and that was that. There is no evidence that she was anything but a housekeeper before or after her marriage, but she was well known to run a strict house. She continued to rule the house after Robert's death.

Robert became Huron's first representative in Parliament in 1835 and held the seat until his death in 1841. William ran in his brother's place in the General Election that year and lost in the vote but won on appeal. He was re-elected in 1844 but resigned in 1846. He died two years later.

Tiger Dunlop had a fund of stories to tell and there are a fund of stories about him. He once gave three reasons for not going to church: first, a man was sure to find his wife there; second, he could not bear to be at a meeting where one man dominated the conversation; and, third, he never liked singing without drinking. He loved his liquor, which he kept in a cabinet on wheels called The Twelve Apostles. One bottle contained water and was called Judas.