Bromo(chloro)fluoro(iodo)methane is supposed to have all of the stable halogens a part of this molecule: fluorine, chlorine, bromine, and iodine. Can it really able to be synthesized and if so could it actually not decompose the moment it goes outside of the lab?
It may be possible in theory, but as yet no synthetic route to it has been found. A compound is known with hydrogen in place of the iodine (bromochlorofluoromethane). This latter compound has found some use in research on chiral compounds, which both molecules given here are. Bromochlorofluoromethane proved difficult to separate into its enantioners because it hydrolyzes readily and lacks suitable functional groups, but we now have multiple techniques available to resolve this compound (and which, likely, have found other such uses). See the following WP articles on Bromochlorofluoroiodomethane and Bromochlorofluoromethane.