C-type asteroid
The largest unequivocally C-type asteroid is 10 Hygiea, although the SMASS classification places the largest asteroid, 1 Ceres, here as well, because that scheme lacks a G-type.
Extraterrestrial skies
The asteroid 87 Sylvia is one of the largest main-belt asteroids and the first asteroid observed to have two moons. These moons, Romulus and Remus, would appear roughly the same size. Romulus, the farther one, would be about 0.89° across, slightly bigger than the closer but smaller Remus, which would be about 0.78° across. Because Sylvia is far from spherical, these values can vary by about a little more than 10%, depending on where the observer is on Sylvia's surface. Since the two asteroidal moons appear to orbit (as best we can tell) in the same plane, they would occult each other once every 2.2 days. When the season is right, twice during Sylvia's 6.52 year orbital period, they would eclipse the Sun, which, at 0.15° across, is much smaller than when seen from Earth (0.53°). From Remus, the inner moon, Sylvia is huge, roughly 30°×18° across, while its view of Romulus varies between 1.59 and 0.50° across. From Romulus, Sylvia measures 16°×10° across, while Remus varies between 0.62° and 0.19°.