SPRINGFIELD, USA: Woohoo! Finally, after decades of waiting, The Simpsons Movie is here. A global phenomenon, the show has changed our language, our culture and the way we look at ourselves.

But why is it so successful? Is it the scripts? D'oh!, Ay Caramba!, Kwyjibo!, Yoink and Okily-Dokily! are all now Simpsons catch-phrases which have entered the daily vernacular.

Is it the characters? Since premiering in December 1989, the main characters include Homer, Marge, Bart, Lisa, Maggie, and a cast of literally hundreds of supporting roles.

Well, to be frank, no. As all Simpsons fans know, or suspect, the main reason the show has prospered is because of the pets - who can forget Santa's Little Helper (SLH), Snowball, Mojo, Pinchy, Laddie, Princess, and the celebrated Stampy? These are just a few of the many pets that have appeared during the shows' 18-year run. As typical of The Simpsons zany story lines, the pets would normally get in more trouble than their owners.

In the leadup to the July 27 worldwide release of the Simpson's movie, here's a quick rundown on some of the shows' most loveable and memorable pet moments:

Santa's Little Helper (SLH) - A greyhound Homer and Bart adopted after he continuously lost at the Springfield Downs racetrack when his former owner threw him out on Christmas day. Although constantly being tested by Homer's, Bart's, Snowball's and even super-dog Laddie's sometimes hurtful antics, SLH remains a loyal, lovable pet for the Simpsons, especially Bart.

Snowball - Lisa's pet cat. While there are actually five Snowballs at one time or another, due to untimely demises, Snowball V is renamed Snowball II to save Lisa from buying another food dish with the new name. When the newest Snowball survives being hit by a car, Lisa thinks that she has finally beaten the curse of her pet cats all accidentally dying in the most weird circumstances.

Mojo - Homer's pet helper monkey, who first appeared during the ninth season of the show, when Homer found a way to be even lazier - get his monkey to do everything for him. Mojo and Homer became close and even became food mates, but it all fell apart when Mojo became even lazier than Homer.

Pinchy - Another of Homer's pets. Pinchy is a lobster Homer purchased to fatten up and eat, but when it was finally time for the the pet lobster to hit the stove, Homer is too emotionally-attached, and can't do it. However Homer accidently boils Pinchy to death when he gives him a hot bath, and so mournfully eats his best friend.

Laddie - The super-collie which Bart orders from a catalogue using a fake credit card. Laddie was trained to do almost anything including flushing the toilet and even do a host of different household chores. When Bart could not pay his credit card bill, the repo man came to take Laddie away.

Princess - Lisa's pet pony. Princess was a gift from Homer to regain Lisa's love after Homer repeatedly disappointed her on many occasions. However Homer can't afford to to keep the pony, he gets a second job on the graveyard shift at the Kwik-E-Mart to augment his meager income. Lisa gives her pony back after seeing her father almost kill himself working two jobs.

Stampy - is an elephant that Bart won when he entered a radio contest. Although the main prize was actually $10,000, the elephant was thrown in as a gag prize. However the DJs get the suprise of their lives when Bart chooses the elephant over the money. Homer plans on selling him to a poacher and ivory dealer but later changes his mind when Stampy saves him from drowning in a tar pit.

So how have pets always managed to dominate many of the Simsons' most-unforgetable episodes? One reason is that the shows' creator, Matt Groening, is actually a pet lover himself. He has three cats which live with him. Another of the shows' developers, Sam Simon, is an absolute dog lover. Simon has spent millions of dollars on the Sam Simon Foundation which rescues abandoned dogs and trains them to become hearing dogs for people who are deaf.

On July 27, 2007, the much-awaited, The Simpsons Movie will finally be unveiled to the viewing public. Undoubtedly the pet dogs, cats, elephants, iguanas and other animals will have starring roles.

For a complete list of pets and animals from The Simpsons series, click here.