Think of you entire event sheet as a one big loop. Each frame goes through the event sheet once.
What is happening your case is each frame the event is Creating the Mole object and then setting the animation. So if you game is running at 60 frames per second, you are creating 60 new mole objects each second.
I hope that makes sense.
IF you want it to just happen once, you can deactivate the Mole1 group after you set the animation. Then it won't happen again until you activate the group again.
There are better ways to handle what you are trying to do, but my suggestion should work.