Minecraft Dungeons

This one is pretty simple. First, unlock the level Radiant Ravine by finding the secret scroll in the level Coral Rise.

Then do a run through of Radiant Ravine on a low difficulty. Make sure you have an Ice Wand artifact equipped (or in your inventory to equip once you find a glow squid). When you find a glow squid, simply kill it with the Ice Wand.

In my first run through on Radiant Ravine, I found four glow squids toward the end of the level, so you should have plenty of chances.

You might want to have a fishing rod artifact on you as well, so you could use that on the glow squid first to gain progress toward the achievement, "Gone Fishin'".

If you don't have an Ice Wand yet, this info will help you obtain one:
Added with the Creeping Winter DLC
Dropped at Frosted Fjord and Lone Fortress
Chance to be obtained from the Wandering Trader.
Chance to be obtained from the Mystery Merchant (? and Artifact boxes)
Get someone to trade you one

This requires you to find an Ice Wand artifact from the Creeping Winter DLC levels or to purchase one from the camp merchants. Now, head into the Radiant Ravine secret level on a really low difficulty so you can easily run through. You are looking for squids that sparkle, these are the glow squids and there should be a couple of them on this level. Line up your shot and use your Ice Wand to kill the glow squid.