4 dark aliens seen since an airplane between Warsaw and London

On February 15, 2017, a man was in an airplane between Warsaw (Poland) and London (England) when he has seen through the window 4 dark aliens standing on clouds over Lodz, in Germany.

Witness statement:

Flying from Warsaw to London Heathrow, looking out the window to my left.
Out of the corner of my eyes I saw these dark, thin figures in the middle of a cloud.
It definitely wasn't a building because we were too high up so I thought they were mini tornadoes
There were 4 figures: 2 tall ones and 2 slightly small ones. They were very close together and they weren't moving at all. They were dark, had a thicker upper body and a thinner lower body. One of them looks like they had wings.
I was in awe and shocked at how it was all deserted then there were these random weird objects just standing on top of a cloud. I took photos and showed my parents and brother the photo and they couldn't believe their eyes. I was also a little bit excited because I have never seen anything like this before.
Flew past the object(s) then it disappeared.