Complete the indicated task to unlock the achievement.

Achievement	How to unlock
A friend in needs	Unknown.
Airborne forces	Unknown.
An eye for an eye	Unknown.
Animals lover	Unknown.
Butchery	Unknown.
Cerebral	Unknown.
Cheeki Breeki	Unknown.
Collectionist	Unknown.
Endangered specie	Unknown.
Fear the player	Unknown.
Heart broken	Unknown.
Hecatomb	Unknown.
Hugger	Unknown.
Marathoner	Unknown.
Natural Born Killer	Unknown.
Ninja	Unknown.
Old school methods	Unknown.
P.R.E.D.A.T.O.R.	Unknown.
Rampage	Unknown.
Serial Killer	Unknown.
Survivalist	Unknown.
Tactile	Unknown.