One of the best jobs in the world is that of the network executive who decides which children's-television-program ideas make it into production. "OK, so we're thinking we have this well-endowed sow named, uh, Piggy who is in love with a talking frog named Kermit. And then we'll have a chef who doesn't speak English and rats who skate in frying pans on dollops of butter!" "Yes, Mr. Henson, that sounds fine. Here's a sack full of money." A similar discussion was probably had about Biglittlethings. The cast of Imago Theatre plays cave people, insomniac hippos, hitchhiking rabbits (pictured) and a zooful of other acrobatic creatures at the Center of Creative Arts (524 Trinity Avenue, University City; 314-725-6555 or www.cocastl.org) this weekend (Friday through Sunday, February 10 through 12; performance times vary). The kids will love the show, and you'll wonder why you didn't think of this stuff first. Tickets are $14 to $20 and are available through MetroTix at 314-534-1111 or www.metrotix.com.