If you think dinosaurs and dogs are...

If you think dinosaurs and dogs are improbable artists, you haven’t met Tom and Arthur.

The former is the eponymous hero of Tom, written and illustrated by Spanish artist Daniel Torres. This venturesome dino loves to travel and one day arrives in the port of New York. Even in a city of that scale, it’s hard for a dinosaur to fit in. Tom tries on a variety of jobs for size but none is quite right, until he stumbles into his true calling: Spilling paint on himself, he discovers his own aesthetic. As one art critic exults: “He could be the next Pigasso or Andy Warthog!” OK, the humor’s pretty feeble, but the art is sensational--both Tom’s and Torres’. Working in black ink and watercolor, the illustrator demonstrates a mastery of both orderly line--as a draftsman, he recalls Istvan Banyai of “Zoom” and “Re-Zoom”--and color.

Happily the book is large enough to do justice to a dinosaur and a city that’s more than his size.

Art Dog, written and illustrated by Thacher Hurd, may be more modest in size but it’s every bit “Tom’s” equal in energy and imagination. Here’s the story: By day, Arthur Dog works as a guard at the Dogopolis Museum of Art. But by night an astonishing transformation takes place and he turns into--ta-dah!--Art Dog, streaking through the city in his Brushmobile to foil a band of art thieves. Hurd has great fun creating canine pastiches of famous works of art: For example, the plot is set in motion by the theft of the Mona Woofa while Art Dog’s swirling masterpiece, “City Rhapsody,” is a symphonic evocation of Van Gogh’s “Starry Night.” You don’t need to be familiar with art, however, to enjoy the engaging story and the vibrantly colored pages that display it.

What Hurd has done for dogs, author-illustrator Dav Pilkey did several seasons ago for felines in “When Cats Dream.” Now Pilkey is back with outrageous cartoon drawings for Make Way for Dumb Bunnies, pseudonymous author Sue Denim’s new book about America’s favorite hair-brained hares. The most literal-minded children’s book characters since Peggy Parish’s Amelia Bedelia, the bunnies have their usual bone-headed misadventures that may remind some readers a bit too much of Harry Allard’s Stupid family. But no matter, Pilkey’s cartoons are full of laugh-out-loud visual humor--and you’ve got to love characters who watch TV in their pajamas.

Finally, here are two illustrators having fun with format: Both Janet Stevens and Lois Ehlert turn conventional design on its head in their respective new titles Tops and Bottoms, a 1996 Caldecott Honor book, and Snowballs. In each case the art “reads” vertically instead of horizontally. There is less compelling reason for this orientation in Ehlert’s collage extravaganza about the construction of a family of snowpersons than in Stevens’ trickster tale about a family of enterprising rabbits, but both books are diverting and beautifully realized.

TOM, By Daniel Torres (Viking: $15.99)

ART DOG, By Thacher Hurd (HarperCollins: $14.95)

MAKE WAY FOR DUMB BUNNIES, By Dav Pilkey (Scholastic: $12.95)

TOPS AND BOTTOM, By Janet Stevens (Harcourt, Brace: $15)

SNOWBALLS, By Lois Ehlert (Harcourt, Brace: $15)