Commissar Pancake's Handy Guide to FILTHY XENOS SCUM:
1. Does it have armor?
No: BEATING STICKS
Yes: Stun by grenades/gunfire/belittlement. THEN BEATING STICKS.
2. How many claws?
(1) Laugh at the pitiful Xenos scum that attempted to invade Holy Terra with a single appendage
(2) How DARE they try to mock the perfect form that is Humanity!? USE THE BEATING STICKS!
(3) Target the one in the middle! Preferably with heavy weapons.
(4) Use TEAMWORK! Remember: if they're eviscerating your comrades, they're not eviscerating YOU. And when whatever eldritch abomination you are facing is exhausted from mauling your team, BEATING STICKS.