You have PumpfBox and Pumpf sprites positioned on the layout left to the playing screen, when the program starts they start falling out, than you create another enemy from those sprites and you have 2 enemies, but only one is on the screen. If that was the problem, just destroy one enemy.
And to the second problem, on Animation event sheet - Event 5 - you have>
+ PumpfBox: is walking -> Pumpf: Set animation to "laufen"
+ System: Else -> Pumpf: Set animation to "Default"
when PumpfBox isn't walking, you set animation to "Default", and when it collides with the player, it's set to "beiss", but than again it's set to "Default", because PumpfBox isn't walking and so on. When you disable the else event, it works.