Spitting cobras can shoot liquid neurotoxins.
Cobra venom contains neurotoxins as well as other toxins. It is a defensive mechanism, evolved to hurt the things it hits.
Neurotoxic snake venoms hit many of the same targets as nerve gases. Sarin for example hits acetylcholinesterases.
Multifunctional Toxins in Snake Venoms and Therapeutic Implications: From Pain to Hemorrhage and Necrosis
Three-Finger Toxins (3FTXs) Three-fingers toxins (3FTXs) are
non-enzymatic neurotoxins ranging from 58 to 81 residues that contain
a three-finger fold structure stabilized by disulfide bridges... For
example, α-neurotoxins inhibit muscle acetylcholine receptors (nAChR)
(Changeux, 1990), κ-neurotoxins inhibits neuronal AChR (Grant and
Chiappinelli, 1985), muscarinic toxins inhibit muscarinic receptors
(Marquer et al., 2011), fasciculins inhibit acetylcholinesterase
(AChE) (Marchot et al., 1998),...
Snake venom is of course a liquid though it can be sprayed. Usually nerve gases also start as a sprayed liquid that either continues as tiny droplets or volatilizes.
Snake venoms will probably all be proteins and none of the nerve gases listed are. But snake venoms can do a lot of what nerve gases do and additional things besides (check out fasciculins!). So the answer is yes.