You guys really excel at giving no information about the mob, it's spawn time, what spawns it but you are really good at telling what they drop, which is still garbage!
Ran into him today. Level 76 shadowknight with an A5 healer merc. Reefrunner was level 78 and used Ravaging Fangs multiple times throughout the fight. Not especially difficult thanks to the healer merc but did drop me from near full to half health a few times.