This guys are the Nether's version of villagers! They live in colourful villages in the nether and sometimes use nether portals to travel to the other world and get sugar!
For these folks sugar is very important, they are made almost completely out of sugar and through their veins travels piping hot caramel. They can only heal by ingesting sugar so you'll find a nether portal in every of their villages, used to get some sugar from the other world!
If you come across one of them, fear not! They are neutral mobs, will trade with you and only attack when provoked. If you ever kill them one of them (mean!) they'll drop some sugar and a glass bottle.
From preventing the caramel inside them from hardening when they go to the other world, they often carry a bottle with a potion they have invented that allows them to survive in climates colder than the nether.

Their design was inspired by mexican sugar skulls and the colours are similar to the nether so they can blend and hide from mobs.

-rmnoodle