The following link shows a few images of the upcoming Bismark and Ravana mounts. A rough translation is as follows (pulled from Reddit):
HHTurtle
17th of February 2016
Hello!
This is Project Manager M here.
Have you all been fighting the Extreme Primals?
Patch 3.2 will add mounts as rewards for the Extreme Primal fights introduced in Heavensward.
This time the mounts will be birds!
Mount of Ravana!
Mount of Bismarck!
"What is this? I want it!!!"
Additionally, there will also be mounts for Thordan and Sephirot.
Hmm? Of course, it is decided based on who wins the roll!
I didn't finish collecting all the horses but...
If all the different kinds of bird mounts are collected, do you think something good will happen again...?
Patch 3.2 is set to be released next week on the 23rd of February (Tuesday).
Try your best to win your NEED rolls, everybody!
Project Manager M
HHTurtle
17th of February 2016
Hello!
This is Project Manager M here.
Have you all been fighting the Extreme Primals?
Patch 3.2 will add mounts as rewards for the Extreme Primal fights introduced in Heavensward.
This time the mounts will be birds!
Mount of Ravana!
Mount of Bismarck!
"What is this? I want it!!!"
Additionally, there will also be mounts for Thordan and Sephirot.
Hmm? Of course, it is decided based on who wins the roll!
I didn't finish collecting all the horses but...
If all the different kinds of bird mounts are collected, do you think something good will happen again...?
Patch 3.2 is set to be released next week on the 23rd of February (Tuesday).
Try your best to win your NEED rolls, everybody!
Project Manager M
 Sylastair Wolfhart Wiki