An astrological symbol.
In ancient times, the bull was a symbol of fertility, and so if you want a baby, dreaming of a bull is a surefire sign that this is the right time to try.
The bull also symbolizes wisdom and security, so a strong and calm bull indicates financial growth through one’s own efforts.
A mad, raging bull, however, hints at financial reverses due to rash and impulsive spending or investing.
See “Calf”, “Cow”.