Bloodborne is the greatest videogames on the planet, and among its many memorable qualities is the NPC cast. World of Warcraft's recent Legion expansion pays tribute to one, namely the old hunter Henryk, and in the beta stage went even further.
It's not the most subtle of nods, with Mad Henryk being a rare NPC that spawns in Val'Sharah after the player gets caught in a bear trap, shouting "Oh ho ho. Well looky here. We got ourselves something new to hunt." Henryk never speaks in Bloodborne, of course, but the reference couldn't be clearer.
One interesting detail, however, is that this reference was initially much more fleshed-out, and included a character called Eileen the Raven - which brings to mind Bloodborne's Eileen the Crow. In Legion's beta form you could begin a quest by talking to Eileen the Raven, which sets the player against Mad Henry (no 'k'). Her dialogue imitates and smooshes-together some of Bloodborne Eileen's lines, even rather amusingly echoing her distinctive accent: "That wasn't necessary of ya, but you have my thanks. Don't you ever listen to your elders, druid? No matter, you did save my life. Let me rest awhile. I'll be fine, just wait."
Bloodborne players will immediately recognise this as a reflection of a key event in the game, easily missed, that has a larger symbolic significance within Bloodborne's world. Henryk's tale is a sad one, a hunter who lived tragically long and eventually succumbed to bloodlust and beasthood - becoming no better than what he hunts. Eileen, on the other hand, is the hunter of hunters, and dedicated to saving these fallen heroes from themselves - with the blades of mercy, and a sky burial. Their clash at the Tomb of Oedon is an event that can play out any manner of ways, and with the player's help one or neither can walk away. It represents in microcosm the larger clash of ideologies that lie behind Bloodborne's events.
Perhaps this is why Blizzard decided to be a little less on-the-nose, and remove the Eileen part. Nevertheless the encounter as it survives in Legion has a final, delightful detail. Mad Henryk, after being defeated, drops a 'worn doll' item - an allusion to the plain doll of Bloodborne, and the fact that death is only temporary for both dream-linked hunters and rare mobs in WOW. After the encounter the otherwise-useless worn doll can be discarded, after which it follows the player for a minute before disappearing.
Reddit user Anosognosiac has a pictorial guide to the beta Eileen encounter, or you can watch the encounter with Mad Henryk as it exists here. My thanks to Caelyn Ellis for the tip - may the good blood guide your way.