A Florida scuba diver claims he has been best friends with a 15-foot-shark named Emma for almost 23 years now, describing her more like a playful dog than an apex predator.

Jim Abernethy and Emma first met in 2001 when he removed a fishing hook from her mouth, and they’ve been inseparable ever since. Every time Jim goes into the water in the area of Tiger Beach, in the Bahamas, she comes around and rubs heads with him as a sign of affection. It’s not the kind of behavior most people expect from a huge, 15-foot-long tiger shark that could easily tear a human apart, and that’s exactly what makes Emma the perfect poster girl in Jim Abernathy’s ongoing mission to change people’s perceptions of sharks.