ノーマン・ブリッドウェルによる世界的人気の絵本シリーズ『クリフォード』を実写映画化。転校先になじめず、孤独を感じていた少女が真っ赤な子イヌと出会うが、なんと一夜にして3m以上に巨大化してしまい……。
Fearing that he costs too much to feed, Clifford decides to join a traveling carnival so he can enter a talent contest in hopes of winning a lifetime supply of Tummy Yummies treats. Joined by his friends Cleo and T-Bone, Clifford meets up with Shackleford the High-Flying Ferret and Rodrigo Chihuahua of Steel, as they work together to turn a broken-down act into a record-breaking show.
Lester and Orville accidentally launch a rocket which is supposed to fly to Mars. Instead it goes to New Orleans for Mardi Gras. They are then forced by bank robber Mugsy and his pal Harry to fly to Venus where they find a civilization made up entirely of women, men having been banished.