Full and famous, Conor McGregor rubbed his belly and raised his arms to the delight of an estimated 9,000 fans at his weigh-in Friday.
McGregor (19-2) weighed in at 168 pounds, with former lightweight title challenger Diaz at 169, before Saturday night's UFC 196 main event at MGM Grand.
"Weight should never be an issue," Ireland's McGregor said after stepping off the scale. "Champions should be able to go up and down and fight any challenge that comes before them. So I'm looking forward to going in there [Saturday] night fresh and put on a show for the fans, because I always step up for the fans."
In the co-main event, women's bantamweight champion
Holm (10-0) is defending the belt she took in November in a huge upset by ending
Second-ranked contender Tate (17-5), with four consecutive victories since her late-2013 loss to Rousey, presents an experienced, well-rounded foe for Holm, a former boxing world champion.
"A whole new training camp, whole new nerves, a whole new fight, whole new work in progress," Holm said. "November's fight was back in November. I've got to be ready for [Saturday], so I'm ready."
Holm is a minus-300 favorite over Tate at MGM Resorts' Race and Sports Book.
McGregor's eagerness to fight at the weight he typically trains at is a bold stroke by a 27-year-old looking to further boost his reputation as someone who will fight anybody anywhere. In December, he ended the 10-year unbeaten run of Brazil's Jose Aldo to claim the featherweight belt in a 13-second knockout.
A solid performance Saturday, McGregor said, probably will push him to seek the welterweight belt against veteran champion Robbie Lawler in what could be the main event of UFC 200 in July at Las Vegas' new T-Mobile Arena. No UFC fighter has ever held two belts simultaneously.
"I wouldn't talk bad about Robbie," McGregor told England's BT Sports earlier this week. "[Lawler] fights with his heart and he's a solid champion. He's been around the game so long. But he's not on my level. I don't feel anyone in that welterweight division [is] on my level."
McGregor doesn't hesitate to talk ill of Diaz, however, and he again chided the Stockton fighter as they neared each other at the weigh-in stare-down for cameras.
McGregor said on stage that he thinks Diaz (19-10) is out of shape.
"I was just giggling at his little soft body," McGregor told UFC broadcast analyst Joe Rogan after covering his mouth in laughter and gawking at Diaz. "How can a fat guy be so skinny at the same time? It amuses me. I'm looking forward to going in there [and putting] the martial arts back into the game."
Earlier in the day, McGregor told CNBC during a joint appearance with Diaz that he'd "breeze" past a $10-million payday Saturday, including his $1-million disclosed purse — a first in UFC history — plus various bonuses and sponsorships. He then pointed to how Diaz is profiting, too, after his $40,000 guaranteed purse in December. He repeatedly asked Diaz to bring him a cup of coffee.
The anchor's laughter at McGregor's wit led to Diaz leaving the set early.
"The main thing in this game is either to be me or fight me," McGregor said. "Everything else is peanuts."
McGregor's advantage with speed, reflexes and acrobatic kicks makes him a minus-550 (more than 5/1) favorite for Saturday's bout.
Diaz, a skilled boxer and jujitsu technician, was far more succinct in his comments on stage Friday.
"I'm here to kill or be killed," he said.