(CNN) In the 1970s, fans of the San Diego Padres had little to cheer about on the field. But in 1974, a dancing man in a chicken suit changed everything.

Soon, crowds were filling stadiums around the country -- not to watch the Padres, but to see what the San Diego Chicken would do next. He paved the way for other mascots, like the Philly Phanatic and The Gorilla, as well as a generation of designers, like Tom Sapp.

The San Diego Chicken first appeared in 1974 and paved the way for a generation of sports mascots.

In 1980, Sapp was watching his beloved Georgia Bulldogs take on their hated rivals, the Florida Gators, when something caught his eye.

Roaming the Florida sidelines was a performer in a menacing-looking alligator costume. On the Georgia side of the stadium was -- "Fluffie," a gray dog mascot, who looked about as intimidating as his name would suggest.

At the time, Sapp was a creative director at an advertising agency. But he decided his school needed something a little more fearsome before the two teams faced off the next year.

Years before as a student, Sapp had designed a protoype for a bulldog mascot with rippling muscles. He found the old design and pitched it to the team's coach, Vince Dooley. Dooley loved the idea, but next year wouldn't cut it. He wanted the new mascot on the sidelines in a few weeks for the Bulldogs' showdown against Notre Dame in the Sugar Bowl.

Tom Sapp, left, and his friend Mac Talmadge, far right, introduce Hairy Dawg to former University of Georgia head football coach Vince Dooley.

So, Sapp set up a work station in his basement, where he and a friend built the first costume. On January 1, 1981, "Hairy Dawg" made his debut on national TV at the Sugar Bowl. Georgia went on to win the game to capture the national championship, and the result was a victory for Sapp, too.

"It got on ESPN and I started getting calls from all over the country to help people concept and design an original character," said Sapp.

In the years since, Sapp has designed hundreds of mascots for sports teams, universities, business and nonprofits as a creative director for International Mascot Corporation and his own design firm, Real Characters Inc.

Mascots run the gamut, from animals and warriors to the downright bizarre. Any fans of the UC Irvine Anteaters happen to be reading?

But building an iconic mascot takes more than just a chicken costume and some dance moves. Here's how these characters come to life.

Every mascot needs a story

Before a mascot is ready for prime time, the most successful ones are born from a great idea. Sapp advises that teams first consider what they want a character to convey. Sometimes, it's a team's history, brand or name, but for those without a storied past, Sapp and his crew can create one.

"You may have a back story, or we'll help you create a back story about your character," Sapp said.

The next step is deciding what is expected of the new mascot. Is it simply a walking advertisement? Or is the mascot going to be flipping off trampolines and dunking basketballs? More adventurous mascots like the Atlanta Hawks' Harry the Hawk require designs allowing more flexibility.

"We don't just have a tiger costume sitting on the shelf that we just stick a T-shirt on and a logo and that becomes your mascot," said Sapp. "We always do something that makes it unique to your business, team, school -- whatever it is."

The Philly Phanatic is one of the strangest and most recognizable mascots in sports.

It's all in the eyes

Once the design is ready, it's time to turn the sketches into a costume, and it's the details that can make or break a mascot.

"I think all the personality of a character is in the eyes," Sapp said. "And I don't like screen eyes -- I like them shiny and wet looking."

As important as it is for the character's eyes to look realistic, it's even more critical that the performer inside can see. Sometimes, this requires a little creativity; Sapp's recent costumes for the Angry Birds movie let the performers see through the birds' prominent eyebrows.

Building a full mascot costume typically takes six to 12 weeks, but can be done in as little as a week.

Once the costume is built, Sapp said he always pays close attention to how the mascot looks on a performer at different distances. A memorable mascot must look just as real to a fan shaking its hand as it does to another watching it on TV.

"You walk up to a Mickey Mouse costume at Disney World, that's Mickey Mouse -- that's not a kid in a costume. That character has to be real."

The art of the performance

A great concept and an eye-catching costume are nice, but no mascot is complete without an engaging performer inside.

Few in the business have been at it longer than the man behind Rocky the Mountain Lion, the Denver Nuggets' longtime mascot. "Rocky," who's in his 27th season donning the costume, has asked to remain anonymous to appease his lion taming superiors, but said the toll the job takes on his human body is very real.

"A lot of people think it's not a full-time job and that we're just doing it for a couple beers," Rocky said. "There are broken bones. There is stress on our bodies -- many times after a game I'm dehydrated to the point I need an IV."

Not only is mascoting grueling, but it requires a pretty diverse set of skills. Unlike an emcee, mascots have to rely exclusively on nonverbal communication to entertain and excite a crowd.

"[A mascot performer] is not just a gymnast or an athlete and not just a comedian," Rocky said. "But to be able to draw a smile from people of all ages, without showing expression, without a voice ... I think it takes a certain mentality and a certain drive."

Rocky said he still gets nervous before certain stunts, but what keeps him suiting up is the same thing that makes mascots a critical part of American sports culture.

"I love entertaining, I love commanding a crowd, and I love interacting with [people of] all ages."