Jeff Chapman (September 19, 1973 - August 23, 2005), better known by the pseudonym Ninjalicious, was a Toronto-based urban explorer, fountaineer, writer and founder of the urban exploration zine Infiltration: the zine about going places you're not supposed to go. He was also a prominent author and editor for YIP magazine, as well as its website, Yip.org. Chapman died of cholangiocarcinoma on Tuesday, August 23, 2005 at the age of 31 - three years after a successful liver transplant at Toronto General Hospital (a location he loved to explore). Doctors claimed that Chapman's illness was caused by coming into contact with carcinogens during exploring, but his wife confirmed that Chapman had been diagnosed with auto-immune diseases well before he became an avid explorer. It was his extended stays at hospitals that got him hooked on exploring institutions. She expressed her belief that his exploration did not directly cause his death.