They're Mutt and Jeff, Toody and Muldoon, David and Goliath reincarnated, but with their own blend of slapshtick humor added to the act. They are Rooster and Sweets, ABC's comic twosome who spend two hours tonight trying to solve an arson case in the pilot "Rooster," airing at 8 on Channel 7.

Leprechaun, gnome, little guy, munchkin.

A-frame, giant, pregnant blimp, tent.

These are just a few of the terms of endearment thrown back and forth by Paul Williams, who plays the short one, Brewster (Rooster) Steele, and Pat McCormick, who is William (Sweets) McBride. These two know how to call 'em, and they do just that -- you can guess the next peewee joke will pop up right after the commercial.

But sandwiched in there between the too-many puny puns and giant jokes, a plot emerges.

A fire has broken out at a candy warehouse. . Rooster is dragged away from one of his favorite spots -- the chest of a Raquel Welch look-alike at a local disco. As police department shrink, he must go up and save a woman perched high on a ledge. She takes his advice and jumps. He takes off his cowboy hat and does the same.

"We're dealing with a sick man," Rooster says in melodramatic earnest, barely sitting up in the safety net, "and I'm gonna catch him."

Meanwhile, the dopier half -- Sweets, a former cop turned insurance investigator -- is with some old police buddies, losing at poker. He calls his ex-wife, Irene, who remains only a voice on the receiver throughout the movie. He asks for money. She says no, but first tells him about a fire he can investigate. Thus are born Rooster and Sweets.

The quest for the arsonist leads the daffy duo on a series of interviews, encounters and pratfalls.

Among the potential suspects: one of the partners in the candy company, played by John Saxon.

And there's Jill St. John as Joanna Van Eggar, the owner of a football team.

They happen upon the squad at practice and take time out for one of the players to slam into poor little Rooster, planting him a foot deep in the turf and giving everyone on the team the chance to make short-stuff aspersions.

Once recovered, Rooster and Sweets find Joanna in the locker room smooching with the quarterback of the team, a cameo appearance by pro football player Dan Pastorini.

They hop in Rooster's tiny MG and cruise from suspect to suspect, a rolling sight gag as Sweets' head bobs over the windshield while Rooster struggles to see over the dashboard.

They stop in on the good Rev. Barnum, Eddie Arnold with a bouffant hairdo. In the background is a properly and primly dressed Marie Osmond singing sweetly on the television. Barnum claims to know nothing.

As does the owner of a sex clinic, but the two have fun investigating his operation.

Rooster and Sweets finally decide to go back to the scene of the fire, where a sinister man with a gun shoots at them in the dark and they take turns saving each other's life.

Before the team figures out who is the real bad guy, they take time out for a few more spins on L.A.'s freeways and Sweets keeps phoning home, only to have Irene hang up on him.

The real suspense, however, comes at the end, where, in keeping with the show -- not one to be shy of cliches -- the story ends with a bang.

"Rooster," though not slated for the ABC fall season, could appear later in the year, if an already-scheduled show falls flat.

McCormick, the big lug, is silly and even lovable. Williams, sometimes Sweets' more serious half, may be a better composer than actor, but in "Rooster" he's more fun to watch on TV than the Orioles.

A steady diet of Williams might not be to everyone's taste, but one night of "Rooster" is fairly digestible.