CHILDREN and animals - they may boost the box office but the combination can also be chancy. To bring them together effectively, a director has to steer a firm line between cuteness and cloying sentiment. Two new releases do this well - The Sandlot and Free Willy. They present a growing relationship between misfit boys and unusual animals which the children first see as monstrous beasts. In both films the boys not only learn to befriend the beast, but come to accept their new stepfathers as people instead of the lesser beasts they first believed them to be. The Sandlot (laser, 101 minutes), directed by David Evans, is an excellent family film. The sandlot itself is a deserted area used by the neighbourhood boys for baseball practice. New kid on the block, Scotty Smalls, is puny, hesitant and having trouble being noticed by his new stepfather. One of the older boys takes pity on him, gets him into the right gear, includes him in the game, and belts the ball right into his trembling mitt. Behind the sandlot stands a tall fence behind which lurks ''the beast'' - a savage, drooling monster who devours every ball that sails into its domain. Smalls ''borrows'' his stepfather's baseball - the one autographed by Babe Ruth - and oops! socks it into the beast's lair. The gang's increasingly ingenious attempts to retrieve the ball become increasingly terrifying to them. The story is narrated by Smalls as he looks back on events from an adult vantage point. The film captures this sense of looking backwards effectively. The perspective of memory makes everything seem larger than reality. The children's reactions are sometimes larger than life and sometimes comically street-wise (their performances are very good). As in To Kill a Mockingbird, The Sandlot wryly explores how children make monsters of the unknown and how the mythical beast roams childhood memories. Free Willy (laser/video, 112 minutes): Awesome is a pod of killer whales muscling through the waves, and it will be a terrible thing if our children's children outlive them. Free Willy, directed by Simon Wincer, pays homage to the beasts and proves fine family fare. Willy is captured by the Pequod (shades of Moby Dick ) and boxed into the training pool of the N. W. Adventure Park. There he meets Jesse, an orphan who has to clean the area he defaced while hiding from the police. Jesse once roamed the streets like a blonde shark, but has been placed with foster parents who are trying to keep him in line. When Jesse first meets the beast, he is terrified - but gradually a friendship develops which is lovingly orchestrated. Both are orphaned and isolated spirits snatched from their free environments and caged into an alien routine. Both long for their mothers (Orcas band together for life) and Jesse is the only person the whale will look in the eye. Eventually Willy refuses to perform for the screaming, slapping crowds, so he becomes worth more dead than alive to his commercially minded owner. As Willy once saved Jesse's life, so the boy must save his whale and return him to his family in the ocean. The fact the real Willy is still cramped in a tiny area, now his part in the film is over, and suffers from skin disease and heat exposure, does affect our viewing, but on screen he is granted dignity and freedom. Laser and videos courtesy of Movieland.