Size: 50000 km - 140000 km
Atmosphere composition: Hydrogen
Usually found in a star's outer or cold zone. They have high core temperatures, but do not radiate much heat. Low stellar radiation and high planet gravity enables them to keep a tenuous surface comprised of gaseous hydrogen and hydrogen compounds. The atmosphere is highly turbulent with wind speeds in excess of 10000 kilometers per hour.
Often sites for atmospheric mining, and great for wilderness refueling if you use hydrogen to get around. Be warned however that this is a potentially dangerous maneuver for a novice pilot in a light ship. Even with an experience pilot and a good ship the refueling manouver is only worth it if you're very low on fuel, since not only has it the potential to destroy a ship, but also fuel is a lot cheaper than repairs.
In additon to a chance to refuel, scanning a gas giant can lead to interesting, but dangerous, encounters.