(adsbygoogle = window.adsbygoogle || []).push({}); does anybody know what the other secret achievment is?

heres a trophy guide, its tells all trophies/achievements You must login or register to view this content.

most likely to be the zombie one.

Revive a team mate using a PaP Ballistic knife.

its one of the last ones I need but I don't play alot of that mode.

Type Zork in the computer.
And
Revive a teammate in zombies with a PaPed Ballistic (shoot the downed teammate with it) from a distance.