The best reason to watch ABC's Sunday movie, Penthouse (Sunday at 8 p.m., Ch. 4) is to get a good look at the beautiful woman who decked Mike Tyson.

As an actress, however, Robin Givens is no knockout."Penthouse" gives you the chance to spend two hours in the company of a psychotic killer, played by David Hewlett, and his captive, Givens. The repartee sparkles more on the supermarket checkout line.

Hewlett is Joey, who starts out the film escaping from the locked ward of a mental institution. He makes a beeline for the glamorous digs of his teenage friend, Dinah St. Clair (Givens).

Joey loves Dinah and initially she welcomes him for old time's sake. She doesn't know he was institutionalized and that he knifed to death a guard who tried to stop him from reaching her penthouse.

She begins to realize that something is wrong when he locks the penthouse door to keep her prisoner. Why there's no spare key around is one of the script's little mysteries.

While Robert Guillaume as record mogul Papa St. Clair tries to bully the copsdownstairs - a hapless hostage negotiator and a hopeless police lieutenant - Joey prusues his imaginary romance and talks about leaving the apartment the same way his mother went. Mommy dearest jumped to her death, a suicide.

The trouble is that Joey seems basically sweet and - at least until it's time to depart - obviously has no intention of harming Dinah. That keeps suspense at a minimum. His libido, as well as the rest of his psyche, is stuck back in early adolescence. Why, the boy isn't even into bondage and doesn't tie up his captive while he sleeps.

If that girl had any of Givens' real-life gumption, she'd have been out ot there and this film would have been history long before it had dragged on for two hours.

- THE CROWD promises to be a lot livelier in the hour before "Penthouse," when ABC airs The Debbie Allen Special (Sunday at 7 p.m., Ch. 4). The show was not available for review, but among those who will be on hand are Whoopi Goldberg, Guillaume, Phylicia Rashad, Philip Michael Thomas and Little Richard.

"I wanted to do something that really warranted the word special." Allen said in an interview, "something that felt like a little musical movie. What I ended up doing was four little musical comedy movies, four musical short stories."

The first, she said, was "The Audition," in which Thomas plays a director-choreographer and Allen and Goldberg are auditioning. Allen said Goldberg sings anddances but refused to reveal her number.

The second vignette, "On Broadway," stars Guillaume as a critic and Allen as the star of a Broadway musical on opening night.

"The next one is 'Blind Date," Allen said. "It stars Little Richard as my blind date. Darling, I'd have to be blind. Seriously, he's so much fun to work with.

"The last one is called 'The Movie.' In that episode my sister, Phyicia, stars as my director. I'm having a hard time because I just broke up with my boyfriend and I can't remember my choreography. That one has a big production nember in Times Square."

- FILMS ABOUT the poaching of wild animals, the death of these animals and the threat to their species are nothing new - we see them coming out of Africa all the time and tut-tut disapprovingly.

Greed, Guns and Wildlife (Sunday at 9 p.m., TBS) puts a new spin on poaching because in this National Audobon Society special the poaching goes on in the United States.

A major target, according to narrator Richard Chamberlain, is the black bear. Poachers sell every part of the bear, from paws to gall bladder, which is considered a panacea in Asian medicine.

The show at one point follows Tennessee and North Carolina game officials who set up "Operation Smoky," a sting operation designed to infiltrate the black market in bears operating in the area of the Great Smoky Mounatins National Park. More than 40 people faced criminal charges; some were jailed, others were given substantial fines.

Poaching goes on from Idaho's Salmon River to Montana, Alaska, Tennessee, Florida, North Carolina, California, Louisiana, Georgia, Virginia and elsewhere. Its targets range from cougars to geese, from bald eagles to elk and alligators.

Word of warning: there are some scenes that will disturb the squeamish.