For the Telefragathon Achievement, you need to teleport 50 Zombies!!! Below is the video and written guide depending on your learning preference! Enjoy!
REMEMBER: You need to buy the telefrag grenades off the wall in the ARMORY (room with the grenade disposal).
For Maximum points, follow the guide below.
Round 1: shoot 4 times, then knife
Round 2: shoot 7 times, then knife
Round 3: shoot 9 times, then knife
At the start of the game, shoot the zombies 4 times, then knife. Once you have 1,450 points, open the door to the ARMORY and then activate the power generator to your left/right (depending on if you started in the hangar/gun deck). You now have 300 points.
Toss ALL of your grenades into the grenade disposal (giant plinko board in the ARMORY). Depending on the amount of points you get, you should be able to buy contact grenades off the wall. The first time you do this, you will receive FOUR more grenades.
Toss ALL grenades again into the grenade disposal.
Buy the telefrags off the wall. Finish off the final zombie by shooting 4 times and then knife.
At the start of round TWO, you will receive another frag grenade, so toss that in the grenade disposal for more points! Shoot the zombies 7 times, then knife. When you have enough points, open the door to the LIFT and stand by the CARGO door.
At the start of round THREE, continue to shoot 9 times, then knife! You should have enough points to open the CARGO doors. Activate the power to your right and then grab the Exo-Suit. Gather the zombies into a pile and then launch your telefrag in the middle of them! Finish the round and do it again!
NOTE: At the start of each round, you will receive a telefrag grenade and a regular frag/contact grenade!
Keep gathering zombies in a pile and you should unlock this way before ROUND 10!