The Tennessee linebacker knows exactly what it is.
That might explain why he had some difficulty describing what it's like to see Darren McFadden line up at quarterback, giving the Heisman Trophy candidate plenty of options with the football.
"Pretty much he's like a-" Mayo said, pausing to find the right word for McFadden. "I don't even know how to explain it. He's just a great running back that can throw the ball."
Sounds simple enough, but actually slowing down McFadden out of the WildHog can be a pain for opposing defenses, as Mayo can attest to.
McFadden sprinted his way into last year's Heisman Trophy picture by putting on a one-man show in a 31-14 win over then-No. 13 Tennessee in Reynolds Razorback Stadium.
The WildHog worked to perfection. McFadden rushed for two touchdowns and threw for a third out of the formation -- all in the first half. In the process, he showed his versatility in front of a national TV audience.
"I don't feel like their defense was ready for it," said McFadden, who finished with 181 yards rushing, 12 yards passing and three touchdowns.
Not surprisingly, Arkansas' coaches studied film of last year's win over Tennessee to prepare for today's highly anticipated rematch at 11:30 a.m. in Neyland Stadium (Lincoln Financial Sport).
The No. 22 Volunteers (6-3, 3-2 Southeastern Conference) haven't forgotten the WildHog, either.
Tennessee devoted a significant portion of this week's practices to getting ready for those times when McFadden will line up at quarterback, fellow tailback Felix Jones will come in motion and only a handful of players know where the football is going.
"We know they practiced an hour on it Sunday -- nothing but the WildHog," Arkansas offensive coordinator David Lee said. "Hey, listen, we're going to get them at their best, and I've never known Tennessee to play anything but great defense.
"We're going to have to really play well."
Especially since plenty is at stake today.
Arkansas (6-3, 2-3) can continue its midseason turnaround, improve to .500 in the SEC for the first time this season and possibly get back into the national polls with a fourth consecutive win this afternoon in Knoxville.
Tennessee, meanwhile, controls its own destiny in the SEC East race. If the Volunteers hope to earn a trip to Atlanta for the SEC Championship Game, they must slow down the Razorbacks and their headache-causing WildHog formation.
So how does a defense do that?
"I don't know because I'm not a defensive coordinator," Jones said. "I really couldn't tell you that, and I don't want to tell the secrets, either."
The Razorbacks used the WildHog only sparingly over the first half of the season.
Arkansas coach Houston Nutt said the formation had lost much of its surprise factor because defenses had a year to study film of it.
But the WildHog made a big return in last Saturday's 48-36 win over then-No. 23 South Carolina.
Lining up at quarterback on 15 plays, McFadden showed his explosiveness in a performance that vaulted him back into the Heisman Trophy race.
The junior tied the SEC's single-game rushing record with 321 yards and one touchdown, and he also threw a 23-yard touchdown pass to Robert Johnson.
"It was a great feeling once you get back there (at quarterback) and you get it going like we had it going. And the coaches, they felt like we had it going," McFadden said. "So they just kept throwing plays in from the WildHog, and we just kept running them and executing them."
Arkansas averaged 11.6 yards on the 15 plays out of the WildHog formation, and it produced 174 yards and two touchdowns.
And as they've done in the past, Arkansas' coaches added a new twist to the formation, this time putting Michael Smith in the lineup to let the small but speedy tailback take the handoff from McFadden.
"We just try to stay one more formation ahead of (defenses)," Nutt said. "And hopefully that keeps them off-balance."