Taliyah? This is the herald of greater things!
This is the final battlecast boys! While you all think of Avatar and Teen Titans, there is only the Evolution!

This is the final battlecast boys! While you all think of Avatar and Teen Titans, there is only the Evolution!

This was a canceled skin for Anivia - Battlecast Anivia, you can see it on the lolwiki of unreleased content along with other canceled skins
It's not necessarily Anivia. The only hint that was close to Anivia we ever got regarding Battlecast skins was the codename "ANV" in the Battlecast Prime Cho'Gath blueprints. But that doesn't necessarily mean it's Anivia either. It's basically all just speculation.
Also, notice how the flying figure in the Battlecast blueprints here resembles a moth or a ray, rather than a bird. It could be a bird, but the wings look nothing like Anivia's. :P
the final battlecast will be anivia... in the corner of a picture, its says .anv and it says .vel .skr and so on for the rest also, the .anv is the only one that has not came out, and it is like 100% anivia ^u^
I just wanted to chime in and say that there was never a "/VEL" in the blueprints. And for Skarner it was "/SKA".
For reference, here is the picture with the blueprints you were referring to: http://2.bp.blogspot.com/-Q9X5o9Ox3R0/UBl6mfbCZYI/AAAAAAAAC8M/hCPzjsaGN-g/s400/BCchoteaser.png
What I want to say is that there was never a confirmation that is Anivia. For all we know, it could even be a new champ. The winged figure doesn't look much like a bird, let alone Anivia. It's basically all speculation simply because 3 letters from Anivia's name appeared as one of the codenames (And they weren't even in order like the rest of the codenames are; Urgot, Xerath, Kog'Maw, etc- But that might not be as much of a valid argument).
So it's not 100% Anivia as much as it is not 100% a new champ. :P
-_-
Also, for more reference, here's another picture of our (possibly the same) mechanical, flying creature, taken from the promotional page for Battlecast Kog'Maw and Battlecast Alpha Skarner:
https://i.gyazo.com/f6eecd91f3a656555581898df4529fa5.png
######ALSO, regarding the topic of this thread- I'm not saying that this champion is Taliyah either (It's probably not her, at least, considering how non-humanoid the Battlecast creature looks.)
All I can say is that it looks really uncanny, gives me those fake UFO vibes I've felt when I was a kid.
Nope, you shall all see!