Little gluttons lol! A goldfish can literally eat itself to death if given unlimited access to food. Ponies can as well, I believe, which is why it is important to restrain the intake. 

Yes, goldfish are live-bearers, meaning that they lay eggs instead of give birth to fry. They can spawn naturally in a pond or in a community tank, but can also be hand-spawned as well. I have actually seen a video of that...the human runs his hands along the goldfish's belly and sides and the fish releases the eggs. The same is done for the male as well.

Oopsies, that was totally a type-o, my bad! That's why I said they lay eggs instead of give birth to live fry. My mistake.  :'D