“‘I’ll follow him to the ends of the earth,’ she sobbed. Yes, darling. But the earth doesn’t have any ends.” -Tom Robbins
We have some pretty good definitions of what it takes to be a planet, and one part of that definition is that a world needs to be massive enough to pull itself into hydrostatic equilibrium. In the absence of external forces and rotation, that means it will be a perfect sphere.
But what about if you allow the other forces to come into play? In addition to the many interesting features you’ll get, one of them is a flattening of your world. So that brings up the question of how flat a planet could possibly be? This isn’t just theory; our own Solar System has a great example that you’ll want to see for yourself!