Night Night Gun or ICER from Marvel's Agents of SHIELD. I've included optional grips.

'The Night-Night Pistol is a non-lethal weapon developed by S.H.I.E.L.D. technicians Jemma Simmons and Leo Fitz. The handgun holds eight dendrotoxin tranquilizer rounds.

The Pistol was first used in a field operation by Phil Coulson to neutralize Akela Amador. Coulson later employed the Pistol again in a failed attempt to subdue Chan Ho Yin.

Ward later insisted that Fitz redesign the Pistol to make it a single ounce lighter, although, it never is made lighter. When the team visited the Hub, Jemma used the Pistol to incapacitate Agent Jasper Sitwell in order to allow Skye to break into S.H.I.E.L.D.'s mainframe. Melinda May later used the Pistol to tranquilize Hannah Hutchins in Batesville, Utah.

When Fitz, Grant Ward, and Coulson accompanied John Garrett to get Skye's medicine, Fitz used the pistol as a defense weapon while Coulson used a lethal pistol and Garrett and Ward used machine guns.

This technology later gave rise to the I.C.E.R.s.' - agentsofshield.wikia.com