The other solution to this has great info- but I just got this achievement last night and I wanted to give a few more random insights for first timers. However, full disclosure our queen glitched- she landed on the ground after a couple minutes and then never took flight again. There were a bunch of us and we took her down in probably 12-13 minutes.
At this point, the main issue is getting enough people to help with the queen. Or at least that’s what I thought would be the issue because that’s what everyone is saying. I have been server hopping a bit for exp, and each time I check the silos on the map to see if it looks like other players are prepping to lunch a nuke. Last night I messaged a couple guys at a silo to check if they were going to launch at the fissure prime site, and sure enough they were. I ported to that silo and helped them finish it. This is a good idea to help with because they can be a pain! As soon as prep finished in the last room I quickly messaging every player on the map (click on their white dot and send message) who was over lvl 40 “queen help” and over 10 players showed up! TBH this game has so little going for it I think high lvl players are bored and if you spawn a queen you are giving them something to do. And low level players make for more targets to distract the queen.
-2-3 other regular scorchbeasts appeared for us. I was told this is normal.
-Bring multiple weapons. You will be dispensing so much damage your weapons will break during the fight. I was down to my 3rd melee weapon before the end. I used blade of Bassett, black diamond and the Gracknock axe
-the queen is a “legendary” creature, meaning her health will regenerate after it goes down 50%. So expect to need to take her full health down 1.5x.
-the achievement DID pop for everyone who still didn’t have it. Although it popped for me a little later than I would have expected.
-the game did not freeze for anyone. I think the servers are a bit more stable now.
-I was a lvl 83 with a 1 handed melee build. But there’s no way of knowing how much damage individual players did.