Download Minecraft PE 1.17.0 FULL for Android Caves & Cliffs you can here. Mojang added many new features such like: Axolotl, Goat, Glow Squid, Powder Snow, Glow Lichen, Spyglass and many other stuff. You can see new mobs, blocks and instruments.
Full changes you can see on official website:
some new stuff you will be able to see on these screenshots
Beautiful animal which was voted on Minecon Live 2019. They ram, high jump and live on extreme hills. Do not forget they you can get milk if you use empty bucket.
New plants and berries
Dripleaf, Moss Block, Azalea, Glow Berries and much more!
This block makes your walk slower if you stay on the powder snow. The same situations with creatures
Huge structure will be generated around Overworld. It also contain of new blocks.
New mob can be found under the water. He is passive mob but he will attack some water creatures. You can see Axolotl in different colors.
He is under water animal. If you want to get Glow Ink Sacs just kill the mob.