All the good things.
Tʜᴇ lᴀᴛest ɪɴ Mojᴀɴg's Caves & Clɪꜰfs snapsʜᴏᴛs ꜰᴏʀ Mɪɴecraft ɪs ᴏᴜᴛ, ᴀɴd ɪᴛ's ɢᴏod ɴᴇᴡs ꜰᴏʀ pʟᴀʏers ᴡʜᴏ ʟɪᴋᴇ stuff ᴛᴏ gʟᴏᴡ. Lᴀst ᴍᴏɴᴛʜ ᴡᴇ ɢᴏt gʟᴏᴡɪɴg squids, ɴᴏw ᴡᴇ ɢᴇᴛ gʟᴏᴡɪɴg ʙᴇrries, ᴡʜɪᴄʜ ɢʀᴏᴡ ꜰʀᴏᴍ cave vɪɴes. Not ᴏɴly ᴅᴏ tʜᴇse babies gʟᴏᴡ, ʙᴜᴛ ʏᴏᴜ cᴀɴ eᴀᴛ tʜᴇm ᴛᴏo, makɪɴg ꜰᴏʀ a ᴠᴇʀʏ versᴀᴛile delicacy.
Overall, this snapshot demonstrates just how much cooler spelunking is going to be upon Caves & Cliffs' final rollout. The combination of cave vines and glow berries will result in some nice little subterranean gardens, as will the new decorative blocks in the form of hanging roots and rooted dirt. There's also moss and spore blossom, as well as Azalea bushes that can grow from moss blocks once bone meal is added. These bushes can flower, too.
In keeping with the dank underground theme, dripleaf has been added: you'll find it growing on clay or underwater. You can stand on the bigger variants of these, but only for a while, as they'll start to tilt.
They're the biggest additions—you can read the changelog here. To enable snapshots, activate them from the "Installations" menu in the Java Edition launcher. The full Caves & Cliffs update is expected to release some time mid-year, and to see what else is happening and what will happen in 2021 check out the state of Minecraft.