Mobs launching players when in creative mode

What I expected to happen was...:
When I contact the mobs I expect to stay close to them so I can build around them and kill them.

What actually happened was...:
When my player contacted the mobs I was launched a varying amount of blocks away. I was launched anywhere from 5 to 600 blocks away and I nearly lost what I was building because it went out of render distance. 

Steps to Reproduce:
1. go on a superflat world in creative mode
2. ...double tap to fly
3. ...fly into a mob and watch it launch you away