Badabee badablurb.

We still highly recommend backing up your world before loading it in this snapshot.

Changes in 21w40a

World generation tweaks
Changes to mob spawning
Copper Ore now drops 2-5 (from 2-3) Raw Copper items
In the Stonecutter, a Block of Copper can be converted to four Cut Copper
A bunch of biome variant with similar features but different shapes have been merged into one, since the shape is controlled independently now
Renamed some biomes

World Generation

Updated ore distribution to make branch mining deep down more rewarding. Updated ore distribution chart
- For example, added more unexposed diamonds
- Iron ore now generates above 80, with more iron ore as you go higher
- Extra gold generates below height -48
Non-cave biomes no longer change with height - so no more savannas in the sky and things like that
Tweaked the relative size of some biomes to match 1.17 a bit closer.
Increased the average size of most biomes (this also means biomes aren't in the same places as before)
Fixed some aquifer issues (a side effect of this is that aquifers are in different places now compared to last snapshot)
Slightly increased the frequency of underwater magma
Increased the amount of dungeons, especially below height 0
Gravel now generates below height 0
Villages are slightly more spread out
Removed water lake features, Aquifers provide local water levels

Axolotls now only spawn in water, above clay blocks, in lush caves
Glowsquids now only spawn in water blocks, under height 30
Cod, Salmon, Pufferfish, Tropical Fish, Squid and Dolphins now only spawn in water from height 50 to height 64
Tropical Fish now also spawn in lush caves at any height
Zombies once again spawn in dripstone caves - drowned can also spawn there however
Goats no longer spawn in stony peaks

Optimized AI for Axolotls, Goats, Hoglins, Zoglins, Piglins, Piglin Brutes and Villagers
Bedrock layers generate dependent on the world seed now

MC-132306 Snowy grass without snow near lakes in snowy biome
MC-169523 As of 18w06a, the sand, clay and gravel blocks no longer generate around small lakes
MC-197688 Mountain Edge never generates
MC-217906 Large amounts of axolotls cause performance issues
MC-225842 Flowers can generate on large plants near lakes
MC-225858 Seeds and flowers appear in ponds
MC-227064 Floating grass can still generate above water lakes
MC-229365 Large amounts of goats causes performance issues
MC-236617 Mountains & Gravelly Mountains use their 1.17.1 biome ID name
MC-236632 Banners without patterns do not render properly
MC-236663 Command blocks do not display command in their UI
MC-236736 No relief on treasure map or explorer maps
MC-236896 Strange mini broken aquifer walls generating commonly on the surface
MC-237490 The bottom parts of aquifers aren't always surrounded by blocks which can occasionally cause them to spill into caves in ways that appear bizarre
MC-237666 Unused biomes still present in game files
MC-237925 Opening world from 1.12.2 (or older) in latest snapshot regenerates random chunks
MC-237933 Sweet Berries generate much too often
MC-237950 Cave vines can generate without tip because prioritize_tip option is negated
MC-237951 Cave vines can generate into water
MC-237962 Entities bob their head up and down when targeting towards the player
MC-238104 Blue Orchid generation has decreased
MC-238265 version.json contains internal revision ID instead of game version ID