When he is not fighting in a cage, the UFC light-heavyweight is a full-time firefighter/paramedic for the Tucson Fire Department.
On Saturday night, the 34-year-old Griggs will be wearing his Grave Digger hat as he makes his UFC debut at 205 pounds against Cyrille (The Snake) Diabate of France at UFC 154 in the Bell Centre.
Griggs (11-2) elected to move down to 205 pounds after losing his UFC heavyweight debut against Travis Browne at UFC 145. He says a shift to light-heavyweight was discussed before his first Strikeforce fight, against Bobby Lashley. But he beat Lashley and two more heavyweights before transferring over to the UFC and running into Browne's flying knees.
That loss — and the fact that some UFC heavyweights have to cut weight to meet the 265-pound limit — prompted a rethink about the weight drop.
"It's a change, there's no question about that," said Griggs, who weighed in at 228 pounds to Browne's 250. "I feel real good. I think it's where I needed to be for a long time.
"I feel a lot more energetic, lighter, (I) still feel strong. I think it's going to be a good weight class for me. ... Fighting the best of the best, it's time to cut down in weight and fight some guys that are a little smaller."
The six-foot-one Griggs, who normally walks around at 235 to 240 pounds, undoubtedly also felt hungrier in the run-up to his Bell Centre bout.
A dietician is helping him cut the weight.
"It's been pretty easy once you get into the groove of realizing that what used to be your snack is now your main meal," he said.
The loss to the six-foot-seven Browne was the first in five years for Griggs, ending a six-fight win streak.
"That's my second loss and neither of them have been fun," said Griggs. "But there's no question it's humbling and you learn a lot from it. It makes you hungry, hungry to get that win again."
Browne caught Griggs with a pair of flying knees — a fake first and then the real thing — and it was all downhill from there. He tapped out to an arm-triangle choke after two minutes 29 seconds.
"A six-foot-seven guy is not supposed to able to do that," Griggs said with a chuckle, referring to the flying knees.
Griggs, who has been fighting professionally since 2005 and never gone to a decision, has been with the fire department for about 12 years.
"It's a great career," he said.
Also a demanding one. His work-day is a 24-hour shift, followed by 24 hours off. That repeats until you've worked five 24-hour shifts then you get six days off.
Essentially you work 10 24-hours days a month and then get the other 21 days off.
Spend that kind of time with your workmates and they become family, especially when the job description involves going into burning buildings while others run out.
He makes his training camp fit by taking time off, making shift trades with his colleagues.
"I take a good chunk of time off so that I can sleep at night and get all my training in," he said.
When he is working, he'll try to squeeze in some mini-workouts at the fire house.
Recently promoted to paramedic, he rides in an ambulance these days but still carries all his fire gear and attends both medical and fire calls.
Griggs isn't the only UFC fighter-firefighter. Bantamweight Eddie Wineland is also a firefighter, as was now retired welterweight Chris (Lights Out) Lytle.
Eric Del Fierro, head coach at Alliance MMA in San Diego which is home to bantamweight champion Dominick Cruz, Brandon Vera and Phil Davis, is also a firefighter.
For a while, Griggs says his employer looked the other way at his MMA career. But times have changed, with the sport getting greater acceptance.
"Now they're very supportive," he said.
Griggs played soccer — which he credits for his agility— and football growing up.
He met MMA veteran Don Frye by chance and ended up training with him.
"He needed some big bodies and I was a big guy," Griggs recalled. "He started putting a whuppin' on me and I ate it up and just kept coming back. And he finally realized that I wasn't going anywhere and took me under his wing."
The two went to Japan together and Frye, who started his pro career at UFC 8 in 1996, eventually coached Griggs in the International Fight League.
Diabate (19-8-3) is a six-foot-six veteran kick-boxer. Griggs plans to bring the fight to him, looking to use his brawling abilities to blunt Diabate's technical striking.
An interesting character in his own right, Diabate has supplemented his income as a fighter and gym owner with stints as a bodyguard, bouncer and stuntman.
Griggs may be smaller this time out but his trademark mutton chop sideburns are as big as ever.
"That's where my power comes from," he jokes.
Married at 19, Griggs has a 12-year-old son and eight-year-old daughter — "and I've got all the grey hair to prove it."
Griggs' nickname came from his training partners, who were the first to note Griggs' heavy hands, all-out style and ability to drop a sparring partner.
"I liked it. It stuck. But I have learned after the years of all the training you've got to ease up a little bit on your partners or they don't come back."