A seeming
non sequitur from
Marathon 2, as uttered by the assimilated bobs. These are alien-produced human lookalikes which are really exploding
booby traps. The only useful ways to tell them from real humans were listening to what they said or shooting them and looking for yellow blood. This was perfectly acceptable, as wiping out every bob of any kind on the level is standard practice for some players.
It was later suggested that this phrase could refer to a portion of a level where
grenade jumping (frog blasting?) a certain long gap would get you to a small secret area, complete with
power-up. This was close to two areas labelled on the overhead map as vent cores.
In a typically
Bungie touch, this also comes up in
Oni, though the exact phrase is "Okay, okay, don't frog blast the vent core!" In this case, it is used by strikers, or at least that's the only enemy I've heard it from. It appeared to be some sort of a rarely-used
taunt. And to cap things off, one of the later levels in
Halo requires the destruction of a number of vent cores.