Asteroids in fiction
After Ceres, Asteroid 433 Eros is perhaps the most-commonly mentioned asteroid, probably because it is one of the largest near-Earth asteroids.
Comet nucleus
The largest centaurs (unstable, planet crossing, icy asteroids) are estimated to be 250 km to 300 km in diameter. Three of the largest would include 10199 Chariklo (258 km), 2060 Chiron (230 km), and the currently lost 1995 SN55 (≈300 km).