Minecraft snapshot 21w03a adds Glow Squids (Axolotls hate them!)
Minecraft snapshot 21w03a is now live, and with it, a new set of pre-release features that’ll be implemented for the Caves and Cliffs update. This time, it’s all about the glow. This snapshot adds Glow Lichen and Glow Squids, which have a number of useful attributes to help you build cool new stuff, including craftable neon signs.
Glow Squids don’t yet spawn naturally in this snapshot, so instead you’ll get eggs for them in your Creative mode inventory. As the name suggests, they glow. And apparently, the recently-added Minecraft Axolotls hate them, as the little amphibians will attack the squids on sight.