Ceres is spherical, Vesta isn't – is it the largest non-spherical solid body in the solar system? I was showing a recent video about Ceres to a friend and we looked up asteroids. Ceres has attained a fairly spherical shape, but Vesta still has a way to go. From Wikipedia:


  Vesta's shape is close to a gravitationally relaxed oblate spheroid, but the large concavity and protrusion at the southern pole (see 'Surface features' below) combined with a mass less than $5×10^{20}$ kg precluded Vesta from automatically being considered a dwarf planet under International Astronomical Union (IAU) Resolution XXVI 5.


I don't know the proper term to use here. Perhaps it is "hydrostatically relaxed" or something similar – I'm looking for the term that would suggest a body has reached a fairly round shape without major excursions, under the influence of its own gravity.

I think Ceres meets this criterion, and Vesta doesn't. Is Vesta the largest such body (by dimension or volume, not sure which would be the most reasonable measure)?
Among the asteroids 4 Vesta is the largest non-spherical object in the Solar system. But far out there in the Kuiper Belt is 136108 Haumea, and maybe yet undiscovered objects, that are very elongated. Haumea is 1,960 × 1,518 × 996 km. That's larger than the 960 km diameter Ceres and hardly spherical with 2:1 proportions. Its fast rotation and composition of malleable volatiles makes this possible. Maybe Haumea is "hydrostatically relaxed" without being spherical?

Haumea images below from Wikipedia.