This appears to happen in both 16w43a and 16w44a. I first noticed the problem specific to Llamas when my wife and I were playing the server running on my machine. My client kept crashing while hers did not. I could not produce a crash report because my client would freeze on my computer, though the server kept running fine for my wife.

She suggested I note I am running the "Launcher Beta", she is running the "old Launcher".

The following images are in sequence as a "Screencapture" of my dual monitor system. For the first image, I waited until memory quiesced around 1G before taking the first image around spawn.

The second image is within sight of the llamas in a pen, memory is at 1.2G, and the F3 screen shows memory is completely allocated.

The third image memory use actually went down, though it still shows "completely allocated" in F3.

I have a period I can interact with the Llamas, in this case I just started moving around them. Just before the last image, control of my view became "drunk and spinny", like the mouse wasn't responding to control while still "moving". Then the screen froze and I did a screen capture at this point for the final image.

All four of these images were in single-player mode under the current 16w44a snapshot. At the time, my wife and I planned to take the Llamas to spawn, but because I can reliably and consistently crash around Llamas but appear to have no other such crashes, we left the Llamas at a location I can get back to without interfering with our normal game play.

Since the game freezes, I can not produce a "crash text file" that would be of more use. I note her client on her separate computer continues to run fine during my client crashes with the server running on my computer, so this appears to be a client-side issue. Her hardware is not exactly the same as mine, though it is the same Lenovo brand and the same memory configuration. I believe I had the same issue under both the game supplied Java and my C:\Program Files\Java\jdk1.8.0_102, but if it is thought this could be the Java version, I can explicitly test this making sure I am ONLY using the supplied run-time Java.

If there is a specific F3 screen I can test with and screen-capture concurrent log output to help find the problem, I would be glad to do so. So far, I can crash pretty reliably just being in close proximity to Llamas without further interaction and in Survival, Creative, and Spectator mode.
***********EDIT 11/5/16***************
I put the snapshot on a separate paid service, then went bouncing around the llamas again. I could not get it to crash as before. So "server + client same machine" crashes, "single-player" crashes on my setup, but with the server on another host it appears I can interact with llamas. The next thing for me to try is the single-player on my own machine again to confirm the freeze, then my wife's machine with the same world. I would welcome other suggestions or an F3 screen that might provide more useful data.