There were various animals on LOST.
Only one had an official name: Vincent, Walt's dog.
Vincent was an alleged survivor of the plane crash hold. He was found wandering the jungle. He was also last seen coming to Jack when he passed on in the bamboo grove.
Some have thought that Vincent could have been a representation of the White Smoke Monster. Vincent was always near the action, especially running off into the jungle "just" before something bad happens or "leads" the people on a chase that helps them find something important. As a dog, people on the island would not see him as a threat. He is the perfect spy. Perfect cover. He could have been Jacob incognito.
The dog has long been considered a liaison between the physical and non-physical dimensions. Ancient Egyptian, Greek, Roman, Celtic and beyond have all prescribed the dog as a sacred guardian of the Otherworlds - those realms outside our daily/mundane experience. If you hear of dogs being symbols of death - this is the connection: Dogs are the guardians of ephemeral domains, and can even serve as spirit guides in non-physical journeys.
As we learned in the End of the series, the sideways world was a place of death, a purgatory limbo of the character souls waiting to be awakened. LIkewise, the island realm could have been real, semi-real or another underworld of the dead (Hell).
The second most significant animal on the series dealt with birds. Fans named the squawking bird that taunted Hurley the "Hurley Bird"because it apparently called out his name. When he asked his friends whether they heard it, they made fun of him. Many fans thought that bird was a warning to Hurley to be careful. Others thought that it was just another clue that Hurley was seeing things, like Dave, as in being crazy.
Many people view birds as a symbol of freedom (such as the American Eagle symbol), or even as symbols of the future. Their ability to soar high into the sky and their proximity with the sky makes them desirable for humans who cannot fly without substitute wings. From time immemorial, mankind has considered birds to be signs of eternal life. Many stories and folklore suggest that birds were taken as signs of renewed life, often as a transition between life and death.Hurley's ability to see and talk to the dead may be part of the Hurley Bird experience. The bird could represent the transition phase from being alive to being dead. In the Middle East and Asia birds are symbols of immortality. In East Indian mythology, all birds represent a "departed soul" and in Christian art, birds are often depicted as saved souls.
The crane is a symbol of long life and immortality. The eagle represents power, resurrection and generosity. The falcon signifies, "A Light that Shines in the Darkness". The nightengale suggests love and longing. The owl is often associated with death and darkness; but it also can bring wisdom, insight and virtue. The peacock heralds in springtime, birth, new growth, longevity, and love. And the tiny sparrow, represents the love of God for even the "least" among us. The Hurley Bird best fits the sparrow symbolism.The other aviary connection to LOST was with Walt. Walt had a special mental attribute which could cause birds to crash or kill themselves. In Australia, he caused a bird to crash during a fit. Outside Room 23, many dead birds were found after Walt's session.
In some cultures, a bird is a symbol of betrayal. In Walt's case, his anger at his situation of being abandoned by his father and losing his mother could have set off his ESP abilities to lash out at inferior creatures.
Then there was the polar bear. A bear often symbolizes contradictions.
Indeed, the bear is asymbol of motherhood and child protection in Native American cultures. Of course a wild bear is potentially explosive so that territorial nature invokes representation o sovereignty, courage and themes of a warrior spirit such as bravery.
In Scandinavian legend the bear was an aspect of the god Odin, and Berserkers were known to wear bearskins to enhance their ferocity in battle. Such vicious looking warriors were insured a victory.
In Greek cult following of Artemis. a god huntress,her maiden devotees would don bear dressings as a symbol of hunting prowess and power.
AncientCeltic lore indicates the bear is grounded in a heroic aspect, we also see it connected to the godess Berne who is associated with lunar movements. Bear meanings associated with the moon continue in Pueblo Indian lore in which the bear is connected to underground temples. Here the bear is said to oversee the movements of the night, and lives in time with the tribe's cycles with the moon.
In fact, many ancient peoples understood the connection of the moon and the bear because of the bear's hibernation patterns. But more importantly, our nature-savvy ancestors recognized the dual nature of the bear.
The nature-based mindset followed the "sleeping" (hibernating) and "waking" nature of the bear and assigned specific meaning to each of these phases of the bear's life. In the LOST ending, the characters must come out of a personal hibernation to "awaken" in the after life. These animals appear to represent the spiritual aspects of the series storylines and theories that surround the show as being one of a journey or passage to the after life.