Cats and Dogs:

If a black cat should cross your path, expect good luck. If a dog howls for no reason, expect a death.

Crows:

Crows are shrouded in mystery, considered to be exceptionally wise and intelligent, some gypsies say that crows live to be 300 years old.  To see one crow means sorrow, and two together means joy. A crow standing in the road signifies a happy journey, while a dead crow in the road, would cause a gypsy to turn back.

Foxes:

If a fox crosses your path, an opportunity will be given to you, if he stops and looks at you your ambitions will be fulfilled.

Horses:

A white horse was once the symbol of the Celtic goddess Epona, and thus should be greeted with respect or you may draw misfortune to yourself. But you can tell the horse your hopes and wishes and they will come true.

Magpies:

Also a member of the crow family are a sign of good luck if two are seen together. One on its own foretells a theft.

Robins and Wrens:

These are both lucky creatures, they bring good news if they fly into your home, but a dead robin or wren near your door is a bad omen. Owls To hear an owl in day time is a bad omen, like wise to hunt or kill an owl.

Rooks:

To have a property with a rookery on it, is seen as very fruitful, but if the rooks should leave then that is taken as a bad omen. In Ireland, when one was buying a property that was blessed with a rookery the deal was considered null and void if the rooks deserted the rookery within one year.

Stoats and Weasels:

To them playing together foretells happiness in the family, but if they are fighting, means squabbles and disputes in the family.

From: Vermont Deadline