Sheep
The sheep is a distinctly flock-oriented animal that follows the others, even if it leads to their death. This trait has led people everywhere to view the sheep as an easily led and collective creature, lacking individual thoughts or impulses. ("Sheeple," as they say, combining "sheep" and "people" to describe a hypothetical easily led group.)
In proverbs across Europe, the sheep is almost always portrayed as a foolish animal, or as a particularly defenseless utility animal. This collective mindset contrasts with individuation, which means that the sheep can be interpreted negatively (depending on the dream’s circumstances, of course). Sacrificing a sheep may indicate a departure from collectivism toward individuality.
On the positive side, the sheep as a symbol of collective values can represent a need to conform, as individualism in some forms can also hinder individuation (for instance, if one considers oneself too special to work within a group or believes everyone else is foolish); individuation is not opposed to social adaptation or basic human decency, for example.
The sheep, and particularly the lamb, symbolize purity and innocence; in Christian art, it appears alongside the Virgin Mary or Jesus. Christ, in turn, is likened to the slaughtered lamb. On the other hand, Jesus is also the shepherd, and people or the congregation are the sheep he watches over.
The animal is valued for its wool, which brings to mind clouds. In German folklore, children were imagined as cloud-like sheep with Mother Earth before being born as humans.
Its white, innocent quality has made the sheep especially vulnerable to evil and sorcery, much like milk—evil is drawn to the good, as if to balance it.