Animal and insect Halloween costumes are always sure to hit the mark for younger kids. Stores sell a veritable menagerie of infant and toddler zip-up suits, such as lions, ladybugs, giraffes and dogs. You can use an eyeliner pencil can draw cute animal noses and whiskers on kids' faces. Parents can decorate baseball hats with floppy felt ears for a puppy or elephant costume, among other possibilities. With the right headdress, the rest of the costume can simply consist of pants and long shirts or sweaters in the appropriate animal colors. For example, if a little girl takes dance classes, she could wear her black leotard and tights as part of a cat costume. With a little creativity, kids can become any animal they wish on Halloween night.