Usually one, occasionally two although twin pregnancies generally abort before birth or one foal is dead at birth or dies shortly after birth. Often both twins die. Successful twins are rare.
Most breeders use techniques to prevent twin pregnancies.
a "stallion" is a male horse so a male can't give birth to offspring.
Horses do not hatch offspring; they give birth to live young. A mare typically gives birth to one foal at a time, although twins can occur but are rare. The gestation period for a horse is about 11 months.
A hinny is a hybrid offspring of a male horse (stallion) and a female donkey (jenny). Hinnies are less common than mules, which are the offspring of a male donkey and a female horse. Hinny tend to have a more horse-like appearance compared to mules.
A dolphin is a mammal, it breathes with lungs, it gives live birth and it suckles its offspring. A seahorse is a fish with a horse-looking head.
Four
Foal.
A Foal
Foal.
The Thylacine gave birth to 3-4 offspring - known as joeys - each breeding season.
A foal is the offspring of a horse but if you must be more specific a girl baby is a philly and a boy baby is a colt.
mule
A foal