Gnat

When allowed into a sick room - removal of ailments

Flying close to the ground - rain

Flying high - good weather

Goat

Associated with Pan (or the devil in some religions)

Meeting a goat when on an important journey - good luck

Meeting a black goat on a bridle path - treasure hidden nearby

Goose

Goose eaten on Michelmas day - good luck

Brown tinted meat - mild winter

White meat - harsh winter

Geese leaving a farm - omen of a fire

A goose laying two eggs - bad omen

Guinea Fowl

Generally good luck

Brings sunshine

Hare

Worshiped in Britain in pre Christian times, then became associated with bad omens. More recently being linked with good luck again (hence the conflicting information)

A guise of a witch

Crossing your path - omen of disaster

Dreaming of hares - bad omen or death

Seeing a brown hare - good luck

Carrying a hare's foot - good luck

Killing a hare - bad luck

Rubbing hare's blood into the skin - cure for freckles

Hedgehog

Another witches guise

Killing a hedgehog - protection against bad luck

Entering the house - very bad omen

Heron

Seeing a heron near the house - bad luck

Killing a heron - extremely bad luck

Horse

Horsebrasses were used to protect horses from witches

White horses - ill fortune

Inhaling a horses breath - cure for whooping cough

Eating a hair from a horse's forelock - cure for worms

Horses standing with their backs to a hedge - rain

Changing a horse's name - very bad luck

information sources:

"Dictionary of superstitions" by David Pickering

"The encyclopedia of superstitions" by Christina Hole