Gas zombies!

Gas zombies are some sort of horrid, reeking zombie that will explode into a cloud of toxic gas when killed or when adjacent to you, so its not a very bright idea to engage them in melee unless you have some mouth protection or can handle the poison debuff. They however have a very low durability , and can be easily dispatched with thrown things. They are as common as smokers,  most dangerous when you don't notice them in a horde until they are close to you, and occasionally leak gas when pursuing you (to make identifying them easier).

I am stuck with the description (and I dont like the name very much), I have been trying to write a passable one for about an hour but nothing good comes to my mind. Could somebody lend a hand?