Creature Slaughter

''Countless Creatures. A bunch of loot. One (to four) Vault Hunter(s). Can YOU (and/or YOUR FRIENDS) survive the Natural Selection Annex?''

Description
Creature Slaughter is a series of five optional survival missions in Borderlands 2 given by Captain Cabrera. The mission series and the Natural Selection Annex in which it is conducted become available after accepting the Wildlife Preservation story mission.

Each mission (round) has the same principle structure which involves surviving several waves of Pandora creatures, including their badass variants.

Each round has the same objectives:
 * Assemble in arena
 * Flip switch
 * Survive round
 * Complete waves X/Y
 * Kill creatures with critical hits: 0/X

Each round also has an optional objective for killing certain number of enemies with critical hits. Regardless of the game mode, number of critical hit kills required for the round remains the same.

Round 1
Survive the Creature's Circle first round!

The round starts with a skag and a spiderant wave, the remaining waves are skags and spiderants simultaneously.

''You survived the first round of the Creature Slaughter. Don't get cocky, kid.''

Round 2
''You've survived the first round of the creature Slaughter, but it'll only get harder from here! Survive the Creature's Circle second round!''

The second round consists of skags and varkids, mostly with level 26. The round will end with after killing a super-badass varkid in wave 5, even if there are other enemies left. There is a possibility of this round spawning 1 or 2 level 27 Ultimate Badass varkids after the super badass is killed.

You've completed round two of the Creature Slaughter, but be careful -- round three is nothing to sneeze about.

Round 3
Welcome to round three!

This round has mostly skags and spiderants ranging from level 27 to 29, but in wave 2, Bedrock bullymongs will make their first appearance in normal mode. Similar to crystalisks, they should be killed with critical hits, as their bodies are almost immune to physical damage.

Three rounds down, two to go!

Round 4
The fourth round of the Creature Slaughter awaits!

This round's enemies are a mixture of varkid, skag, spiderants and additionally, threshers and stalkers with levels of 28 to 30. Special caution should be paid to elemental badass skags, who can buff regular skags with elemental capabilities as well.

Only one round to go -- good luck.

Round 5
Welcome to the final round!

The final round holds a mix of all creatures with a level of up to 31. The most notable enemy here is a badass Pyre thresher. A good strategy is to shoot the critical hit zones of it's tentacles with high fire rate SMGs or shotguns. As a reward for completing the final wave, you will receive Miss Moxxi's Creamer, a rocket launcher that converts some damage dealt to health.

You survived the Creature Slaughter -- congratulations!