tilikum ( – january 6, 2017), nicknamed tilly, was an orca, or killer whale. he was notable for his role in the deaths of three humans, including two trainers. the first death, in 1991, was a trainer at the sealand of the pacific in victoria, british columbia, canada. in 1992, he was moved to seaworld in orlando, florida, united states. in 1999, tilikum killed a trespasser in his inclosure. in 2010, tilikum killed trainer dawn brancheau. this would lead to the documentary movie "blackfish" being based on tilikum.