List of new Minecraft mobs added in 1.17 java edition
There were no new mobs added in Minecraft 1.17.
There are no mobs in this group.
Glow squids where the winners of the 2020 mob vote, and were added to the new terrain generation deep under ground. Goats were the opposite being added to higher parts of the world such as mountain tops. Understandably Axolotls where somewhere in the middle in oceans.