The monster bride, the one who becomes demanding, spoiled and downright evil about her impending wedding (Star Jones, anyone?), is a well-known stereotype. There's even a nickname for her: "Bridezilla."

Now, with more guys getting into the Big Day brouhaha, brides-turned-scary-giant-reptiles have company. Meet "Groomzilla."

"They can turn into little tyrants," wedding expert Sharon Naylor, author of "The Groom's Guide" (search), said of the new frantic grooms. "Even though it's about a wedding, it becomes very territorial."

The transformation from the "just show up in your tux" husband-to-be to the involved, micro-managerial, teeth-baring groom can be explained by the change in who's organizing and paying for that walk down the aisle.

More than 80 percent of husbands-to-be are full planning partners for weddings today, according to Bridal Guide magazine (search).

And 27 percent of couples are paying for weddings entirely on their own, Brides magazine (search) reports — more than the 25 percent who still rely on the lady's family to foot the whole nasty bill.

Then there's the national average cost of a wedding, which rose this year to $26,327 for a 164- guest affair, according to Fairchild Bridal Group (search)'s 2005 "American Wedding Study" (Fairchild owns Brides, Modern Bride, Elegant Bride and other industry publications). Prices soar higher in urban areas.

"The groom is getting more involved and he's obviously paying for it," said Cynthia Hornblower, executive editor of Brides magazine. "He's getting more stressed out. There's a lot more on his plate."

Naylor said she's heard of angry grooms who have "flipped out and gotten rage-angry at the florist or cake baker."

"It's a really interesting time for grooms — they're kind of breaking new ground," she said. "The groom is in the bubble bath trying to relax and thinking, 'How did I get here?'"

Groomzillas in all their ballistic fury are still a small-but-growing breed. Perhaps more common than Scary Groom is Very Helpful to the Point of Excess Groom.

"I'm not going overboard. I'm not Groomzilla or anything like that," said one such fiancé, 26-year-old Jason Miller.

A curious-by-nature engineer, Miller has done the bulk of the planning (with wedding consultant Angela Alcantar) for his Kansas City nuptials because his bride-to-be, Angela Roberts, was an out-of-town grad student for much of their engagement. And truth be told, Miller kind of enjoys the involved groom role.

"I like knowing how everything works and what the schedule is for stuff," he said. "It kind of drives my fiancée crazy. Whenever we meet with someone, I ask any and all questions."

Among his top-of-mind concerns was the music at his reception. He was desperately seeking a laid-back spin doctor who wasn't jockeying for the limelight.

"One thing I was particular about is the DJ. I don't like pushy, game-show host DJs," Miller said. "We would go to every bridal fair — I went to more than she did — and I'd ask, 'What kind of personality does your DJ have?'"

Planning a wedding can be as stressful as a big presentation at the office, and unless they're colleagues already, it might be the first time bride- and groom-to-be are working jointly on a huge project.

In that vein, it might also be the first significant time they get to see each other's management styles and ability to handle deadlines and stress. And the bride is still usually the boss when it comes to throwing a wedding.

"All of a sudden, she's the CEO of you — so how's that going to work?" Naylor said. "You're seeing each other's working styles ... in a partnership on a big project that's emotionally and financially loaded."

Alcantar said the male half of one couple whose nuptials she's coordinating definitely falls into the "Groomzilla" category.

"I have one of those," she said. "He's so anal. He's been a bit of a challenge and we just need to hold his hand a little bit. He's very involved."

Her groom-from-hell wanted 100 hotel rooms reserved by month's end with only two weeks notice, even though his wedding day is five months away.

He was also having meltdowns over where the groomsmen will rent their tuxedos. And there was a change of churches because the guest list has been rising faster than the mercury on a hot day — it's now up to 475, and the original ceremony site could hold only 400.

But let's be frank. Bridezillas haven't gone extinct. They're still out there — and are often the force driving a Very Helpful Groom.

Andrew Gerth, 27, is doing a lot of his wedding planning (also with Alcantar) partly because, he says, he's the calm one while his betrothed, Tiffany Brauer, is the more high-strung of the two.

"I'm not too stressed, but Tiffany gets really stressed easily. That's one of the reasons I'm helping out," said Gerth, of Parrish, Fla.

To alleviate some of the headache over coordinating their wedding from out-of-state, he did contract negotiations on hiring Alcantar, and he's the one running interference between his mother and his soon-to-be bride. But is she a Bridezilla-to-be?

"I think there's potential — there's always potential," Gerth said, chuckling.

Among other reasons grooms are more attuned: Couples today are older (and thus, more opinionated), and over 50 percent live together before they tie the knot, according to Brides magazine, so the hubby-to-be can't help getting involved.

Modern weddings also require monstrous amounts of work, money and manpower for a pair to get hitched without a hitch — so both partners' input is needed. And couples function differently today, with defined gender roles fading.

"Increasingly, young couples see themselves as a support team. They support each other in whatever they're doing," said Charles T. Hill, Whittier College psychology professor and author of the well-known Boston Couples Study (search). "It becomes a couple's responsibility, not just a bride's responsibility."

Sometimes there are other things going on behind the stress about the reception hall, the invitations, the dress and the photographer. While they're blowing their tops over party-planning minutiae, there could be deeper underlying issues they're not addressing.

"The wedding is about the marriage, which gets avoided sometimes," Naylor said. "Focusing on the details of the party and not on the plans for the marriage — beliefs about kids, religion, money — is usually what's underneath the Bridezilla and Groomzilla behavior."

And sometimes these fears and concerns cause severe cases of cold feet.

Franz Wisner, 39, from Los Angeles, didn't have Bridezilla on his hands — he had the opposite: Aloof, Flaky Bride who Wisner said wore her engagement ring sporadically and only took on the job of mailing out the invitations, which were late.

"I picked up the ball and ran with it. I'm much more a list-maker and overachiever type, so whatever she didn't do, I did, with the hope that she'd come around."

She didn't. Instead, she turned into a runaway bride.

"She didn't do much planning at all — that, in retrospect was a huge red flag that I should have paid more attention to. I ended up doing more and more of the planning and footing more and more of the bill," he said. "Then, in the days before the wedding, I got dumped."

Wisner wound up holding the wedding anyway for his family and friends, and then taking his honeymoon to Costa Rica with his brother. His book on the adventure, "Honeymoon With My Brother," (search) came out in February, and a movie based on it is in the works, he said.

Happily, more often than not, the only issue behind brides' and grooms' frazzled nerves is the milestone of going from singlehood to marriage and the job of pulling off the day that starts them on that journey.

"I wouldn't read anything into it other than the stress of the wedding itself," said Hill, the couples psychologist. "Marriage is a huge adjustment. [The wedding is] the first test of the marriage. If they can handle that, they're in good shape."