Blue II, the mascot for Butler, has become quite a celebrity. He has his own Twitter account and even has a martini named after him. (Jonathan Newton/THE WASHINGTON POST)

He flew from Indianapolis to Houston on a Southwest Airlines charter along with Butler’s most ardent basketball fans and was allowed to sit up front so he could stretch out and nap comfortably.

The flight attendant brought him water. Just before disembarking he posed for pictures with the pilot. And since alighting for his second Final Four, he has been staying at Houston’s Intercontinental Hotel, where they’ve named a martini in his honor.

Meet Blue II, the perpetually smiling but vertically challenged 63-pound bulldog that serves as mascot and good-luck charm to the Butler Bulldogs.

On the job since he was a puppy, 7-year-old Blue II is a fixture at Butler’s home games at Hinkle Fieldhouse, where he happily sits on his haunches midcourt as the starters trot out and pat him on the head for good luck. Then he sprints (as best he can) to one end of the court to snatch a giant rawhide bone from his biggest fans in the student section.

NCAA officials nixed the idea of Blue II taking part in pregame festivities during the first two rounds of the NCAA tournament. But once Butler made it to the Final Four, NCAA honchos agreed to let him reprise his on-court role at the 2010 Final Four in Indianapolis.

That’s when Butler officials, led by his caretaker Mike Kaltenmark of Butler’s advancement office, with whom he has lived since he was seven weeks, launched into preparations for his second airplane trip.

(Blue II joined the team on its charter flight to New Jersey’s Meadowlands in December for a game against Duke).

Luckily, Southwest agreed to let him fly in the body of plane rather than relegate him to a crate in the cargo hold.

And the Intercontinental rolled out the red carpet when informed that Blue II was Butler’s beloved mascot. Proceeds from the sale of the Blue II Martini are being split between Houston’s SPCA and the Blue II Fund, which pays for his care.

Back on campus, everyone regards Blue II as a celebrity — not just basketball fans. His Twitter following has topped 5,000. And undergraduates are convinced it’s good luck to pass Blue II on the way to class the morning of a test. If they can pat the bulldog on the head, they believe, they’re sure to get a good grade.

But Blue II has become something of a national sensation leading up to Monday’s national championship game.

On Saturday, he was chauffeured to Houston’s Convention Center at 6 a.m. for a live appearance on the CBS Early Show. Then it was back to the hotel, which waived its standing “no-pets” rule in his honor. Then he had to get to Reliant Stadium hours before Butler’s 5:09 p.m. tip-off against Virginia Commonwealth for his appearance on the CBS pregame show

All that scurrying around is exactly why Butler sent a security detail to Houston in advance in the special car that Blue II likes to ride in, packed with some back-up chew toys and supplies that didn’t accompany him on the plane. That way, Blue II is able to nap in the car, as he’s so fond of doing, and be dropped off directly at the stadium entrance without having to walk too far.

But just like any other great performer, he comes to life the moment the spotlight is on.

“He loves it!” Kaltenmark says. “There’s no place he’d rather be. When we walk down tunnel toward the floor, his pace picks up. He has a nice strut, almost like when you watch the Westminster Dog Show and see the dogs with that beautiful gait, they’re so proud. He just turns it on in the same way.”