Not horns as such (like you would find on a rhino). but - there are 'horns' on some lizards, such as some chameleons.
Yes some breeds of sheep have horns.
Female what? Female goats with horns are common, Female sheep with horns, not so much, but some breeds do.
Depends entirely upon the breed of the bull. Some bulls have no horns (polled) some such as the long horn can have horns that are2-3 ft long
Chameleons that are female usually grow minimal no no horns, while some species do grow horns.
in some species female chameleons grow minimal horns or no horns at all. some females horns are 12-14 inches long while males can grow up to 14 inches long
If aliens exist, some alien races could possibly have six horns.
Yes some breeds of sheep have horns other breeds of sheep have been bred to have no horns ie they are polled
Some species do.
No domesticated goats do not lose their horns. Some farmers disbud their goats when they are little kids so that the horns do not grow. There are also some goats that are born hornless due to a poll gene.
Some deer have horns while other do not, primarily because of gender. A deer's gender may influence the fact that it has horns or not, because most male deer fight.
no one known for sure, but some ideas are:triceratops' horns were used for defense; with the horns, triceratops can recognize others of its kind;the horns made triceratops look bigger NOTE:it's spelled "triceratops" not "tricreatop"