The Centipede Project acquired the specs of the Night-Night Gun designed by Leo Fitz and Jemma Simmons through their infiltration within S.H.I.E.L.D.'s ranks as part of HYDRA, following their multiple encounters with Phil Coulson and his team.
Ian Quinn handed the specs of the gun to Cybertek that transformed it into an aerosol grenade. The grenade was used against Phil Coulson and Grant Ward in order to delay them for capture after they jumped from a train where mercenaries hired by Cybertek were pursuing them. When they awakened from the effects of the grenade, Coulson and Ward thought the train had teleported away. Coulson then procured the grenade and took it aboard the Bus to have its specifications downloaded to S.H.I.E.L.D. Headquarters.
The Dendrotoxin Grenade releases an airborne modified version of the dendrotoxin used in the bullets that renders the targets within its area of effect in a state of unconsciousness that seems as if time has not passed since the explosion of the grenade.