Once the line was in the works, they've closely followed updates about it, wondering what accessories will come with it and critiquing the manes (too skimpy, some say) they have glimpsed from pictures in advance of the release.
About a week ago, some salivated over a picture posted to Reddit of plastic bags full of deflated, yet-to-be-stuffed pink and blue animals in what appears to be a back storage room.
Now, as Build-A-Bear prepares finally to release a new licensed line of My Little Pony products featuring Pinkie Pie and Rainbow Dash, "Bronies" from Cincinnati to San Francisco are planning group outings to their nearest store. Some of them have joked they should alert mall security because they plan to come in costume.
In case it's not already obvious, "Bronies," a combination of "bro" and "ponies," aren't exactly Build-A-Bear's typical pre-teen girl. They are young men - and sometimes women - who have become superfans of the magical, colorful ponies.
The toys from the 1980s have gone through a bit of a renaissance in recent years since the launch in 2010 of an animated television series, "My Little Pony: Friendship is Magic." The show is aimed at girls and follows the adventures of six ponies, each with her own unique personality.
The series has spawned a whole new species of fans, the Bronies, a somewhat puzzling phenomenon that is not easy to explain. Some Bronies, many of whom are college-aged fans, profess to be drawn in by the quality of the animation. Others say it's the story line and multi-dimensional characters. Whatever it is, the subculture that has developed around them takes careful note of every new product and development.
Nick Kuntz, the assistant manager of Star Clipper, the comics and graphic novel store in St. Louis that carries My Little Pony comics, is not a Brony and admits he doesn't exactly understand the appeal.
But he said that while the series is targeted at young girls, it obviously has enough to it to attract a wide fan base that includes high school kids and older women.
"I think maybe it's all of the different characters, which allows people to have their favorite one," he added.
My Little Pony has been one of the Hasbro's brighter spots of late. Company executives singled it out in their most recent earnings calls, saying that it posted double-digit growth last year, helping boost revenue in its girl category along with Furby.
In a news release announcing the arrival of the ponies in stores next week, Build-A-Bear's "chief executive bear" Maxine Clark didn't explicitly mention Bronies. But she said people of all generations love My Little Pony.
"Moms remember this brand from childhood - and now they can share the nostalgia, friendship and fun with their own kids," she said.
The Brony website, The Equestria Daily, has been all over the Build-A-Bear's newest product line. Last September, it noted a market research survey that included My Little Pony among possible options. That post, which garnered more than 200 comments, led to a crisis of conscience among some Bronies who noted the survey was for parents with kids below the age of 12.
"Confound these ponies," said one adult fan. "They drive me to lie about having children."
"Is uncle close enough?" another wondered. "I say it is."
Another exclaimed: "Exclude no age group, pony for all!"
In a post last month, the Equestria Daily posted an item remarking that Build-A-Bear had uploaded pictures of Pinkie Pie and Rainbow Dash to its online database. The ponies, it noted, had loose, brushable manes - as opposed to molded ones as found in some other My Little Pony toys.
"Build-a-Bear sure is in for a surprise when a bunch of Bronies are their biggest customers come April," promised one fan on the site.
The company is hosting special My Little Pony events in its stores next week, at which they will encourage customers and employees to dress up. In addition to making their own stuffed ponies, the retailer says customers will also be able to take a pony personality quiz, recite the "pony promise" and learn how to style their pony's hair with a "special hair care brochure."
And, yes, several optional accessories and add-ons are available, including a hairbrush, signature capes, skirt outfits, a knight costume, theme song and rainbow skates.
And for those Bronies who want more luscious locks for their ponies, they will also be able to buy hair extensions for an extra $4.