A cottony, eastery bunny pantomimes "I wonder. . . Is it there?. . . Will I find it today? . . . There it is. . . Something special. . . for me," and after posing with eyes coyly covered, streaking across a lawn and sniffing behind a tree settles down happily beside his "something special" -- a flower basket filled with cabbage and carrots. Performing rabbits must be rated a cliche even by two year-old standards; however, most of that audience will be happily oblivious to the staging and Tana Hoban executes an unpromising idea with clarity, directness and good taste. In the running for this season's bunny blue ribbon.