The symbol of a fish represents faith, life and plentifulness. It is a recognized symbol of Christianity often referred to as a Jesus Fish.
Horses symbolize courage, death, and strangely, generosity. More specifically a white horse represents good and a black horse represents evil. Horseshoes were believed to be a protection against evil, and in present day are considered lucky.
The meek trait of a rabbit is recognized in the symbolism of gentleness, humility, and self-sacrifice.
A squirrel represents religious meditation and spiritual striving.
In the world of Memento Mori, the crocodile was a symbol of evil. They were hung from the ceilings of cabinets as a reminder of the mortality of humanity.