Most catilppilars are green with black stripes but you may be looking at a Crossstriped Cabbageworm.
black swallowtail
Garder-snake; multi color green, yellow and black stripes length of body.
Black wido
The Cicada Wasp has a black body with blue wings. This wasp also features red and yellow stripes near its stinger.
The Flea Beetle has an outer shell of yellow-white with three black stripes. It is usually found in western North America and tend to hide in the soil.
If the stripes are light in color, maybe even off white it could be a CA king snake.
== ==
zebra fish
Eastern Lubber Grasshopper.
the worst kind
Sea Kraits are white with black stripes. Or black with white stripes if you like to look at it that way.They're a sea snake, highly venomous, but only aggressive when provoked repeatedly.King snakes are also black and white, striped. They are non-venomous, land based and eat other snakes.Hope this helped!
Ariel