It's not easy being green -- especially for an ogre dethroned at the multiplex. The fourth installment of DreamWorks Animation's (NYSE: DWA) Shrek series currently tops the box office, but compared to its predecessors, its initial take seems more lackluster than blockbuster. Fellow Fool Rick Munarriz argues that moviegoers' relative disinterest in Shrek Forever After could bode poorly for Disney's (NYSE: DIS) upcoming Toy Story 3. But before Disney shareholders despair, they ought to consider a few key differences between the two major animated franchises.

Animation ogre -- er, overload
Toy Story made history as the first fully computer-animated feature film when it premiered in 1995. Four years later, 1999's Toy Story 2 earned a plum spot on the list of sequels that improve on their originals. Both films still hold perfect ratings of 100 at movie-review-aggregator site Rotten Tomatoes.

The original Shrek arrived in 2001, poking gleefully anarchic fun at Disney's fairy-tale classics, and earning more than $266 million and a 90% fresh score from Rotten Tomatoes. Shrek 2 did even better in 2004, raking in a whopping $436 million while still maintaining an 88% fresh rating from critics. But the wheels started to come off the pumpkin coach with 2007's Shrek the Third; it still made a kingly $320 million, but its flabby story and quickly dated gags made critics hold their noses, plunging to 41% freshness.

With goodwill for the franchise thoroughly spent by three cranked-out films in just six years, it's no wonder audiences aren't rushing to embrace film No. 4 -- especially given the lingering odor of Third's disappointment. If reviews had hailed Shrek Forever After as a return to form, maybe its big green antihero would have enjoyed a bigger opening weekend. But thus far, it's only limped to a 52% fresh rating.

Dusting off the toybox
In short, every single movie in the Shrek franchise has debuted in the gap between the last Toy Story film and the new one. As Shrek, Donkey, and friends have apparently worn out their welcome in an effort to shovel audiences' cash into DreamWorks' coffers, viewers have built up their anticipation for more adventures of Woody and Buzz Lightyear. The Toy Story films still enjoy healthy sales on home video, and the characters have spent more than a decade becoming staples of real kids' toyboxes and a whole flotilla of Disney merchandise. More importantly, the fun of the first two Shrek films has been tarnished in hindsight by their increasingly rote sequels, while the Toy Story films still enjoy a reputation as timeless family classics.

This may have something to do with Disney's and DreamWorks' differing approach to movies. In a 2007 Wired profile, DreamWorks Animation chief Jeffrey Katzenberg trumpets his preference for quantity over quality -- as many films as possible cranked through the pipeline, each stuffed with bigger, broader, crasser gags. ("It's great," the article quotes Katzenberg as saying about a sequence in progress from Madagascar, "but what I think you need to do is have her kick him in the nuts.")

In contrast, Toy Story creators at Pixar have become famous for their painstaking standards for quality, polishing their stories to perfection even under murderous deadlines. Unlike DreamWorks' mixed efforts, just about every entry in Pixar's 15-year history of feature films has enjoyed resounding critical and commercial success.

Toy Story 3 isn't a guaranteed smash. The law of averages suggests the studio has to stumble sometime, and a long-in-development second sequel to a 15-year-old film is as good a place as any. Meanwhile, recent DreamWorks entries such as Kung Fu Panda and How to Train Your Dragon have drawn praise from critics as big creative leaps beyond the studio's earlier work, suggesting that Pixar can't afford to rest on its considerable laurels.

Still, just because the moviegoing public seems to have chased Shrek back into the swamp, Disney shareholders shouldn't automatically assume that they'll toss Woody and Buzz into the garage-sale bin as well.

Which do you prefer: Pixar's pursuit of perfection, or DreamWorks' fast and funny style? Which makes a better investment, and why? Sound off in the comment box below.

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Fool online editor Nathan Alderman is unconvincingly rendered and questionably animated. He holds no financial position in either company mentioned here, although you're welcome to see all his holdings. You've got a friend in the Fool's disclosure policy.