Gas giant
The smallest known extrasolar planet that is likely a "gas planet" is Kepler-138d, which has the same mass as Earth but is 60% larger and therefore has a density that indicates a thick gas envelope.
(386454) 2008 XM
(386454) 2008 XM is an outstandingly eccentric, sub-kilometer-sized asteroid, with one of the smallest known perihelions among all minor planets. It is classified as near-Earth object of the Apollo group and was discovered on 2 December 2008, by the LINEAR program at Lincoln Laboratory's Experimental Test Site in Socorro, New Mexico, United States.