I was visiting the nether and found a small enclosed area with 3 ghasts spawned right next to each other. I'd never seen anything like that.

There was also some ghasts dying, perhaps suffocating nearby? I didn't find any drops around. This was something I saw in a much older version of PE / Windows 10 but was fixed awhile ago.

I was recording at the time, you can see here: https://youtu.be/5csGJNtgUa4?t=6m