During the Dota 2 Asia Champsionship Grand Finals the devs showed off a new teaser trailer for the upcoming New Bloom Festival event in the game, which is set to take place soon around the Chinese New Year festivities next week.
If you took part in the New Bloom Festival last year you'll know that you had to team up with other players in order to defeat the Year Beast. This year it appears there's a slight twist to the mode (shown in the trailer) - players will have to "tame" the beast instead.
There is also what appears to be an 'announcement' of sorts within the trailer. Towards the end a dragon-like creature flies over Crystal Maiden, and then joins the Year Beast, Maiden, and other ice-wielding heroes. This creature looks like a brand new hero - Winter Wyvern.
I don't know much about Winter Wyvern, but doing a little research online it looks like she's a support hero, using ice abilities (of course) to buff and heal allies, and turn enemies against each other with her ultimate.
Take a look at "The Coming of the Year Beast" teaser below.