Kids love him. TV execs adore him. Sheesh, it’s enough to make out-of-work kiddie-show host Rainbow Randolph puke purple. Ever since that plush, fuchsia-hued, platitude-spouting Smoochy the Rhino started Jiggy Ziggy-dancing in Randolphy’s time slot, he has just one mad goal: turn the rhino into a dead duck. Danny DeVito takes the rhino by the horn to direct and co-star in this gleefully twisted skewering of children’s TV. Robin Williams, his famed wit set a warp, plays ranting Randolph. Edward Norton is the high-minded goodnik whose righteous-rhino creation becomes a sensation, and Catherine Keener portrays a jaded exec who likes kid-show hosts in, let’s say, a grown-up way. Say nite-nite, rhino!