On Christmas Eve the Santa cows arrive to give Elwood and his family a Christmas that they will never forget In a whimsical parody of Moore's ``A Visit from St. Nicholas,'' Mom narrates; the six kids are eating junk food and watching three TVs when eight red-capped cows come down the chimney to sing carols and bring presents--baseball equipment for an all-night game between cows and family. There are plenty of amusing details here, both in the spritely verse and in the mock- earnest pictures of the placid bovines and of a home furnished in ``cute'' souvenir-shop decor. Not essential, but pleasingly silly. (Picture book. 6-10) -- Copyright ©1991, Kirkus Associates, LP. All rights reserved.