TiY posted a new teaser image introducing another member of the team that’s been helping with artwork. The image itself is called werewolf.png which leads us to guess that the creature on the left is a werewolf and could possibly be a new mob, a costume, or something to do with the moon/night phase.
There’s also a new biome behind them in the screenshot. It could possibly be the new “hallowed” biome considering the post topic is “Hawoooooo”. The blue orb in the middle could be a fairy is my best guess with what looks like a little wing coming off of the back.
Lots of fun new stuff! Check out the thread on the official forums for some more guesses as to what is in the picture!