If you haven't seen it yet, check out my list of Jewish graphic literature on Amazon.http://www.amazon.com/lm/R2IIZNVM2VGGX9/ref=cm_pdp_lm_title_1
As mentioned before, I checked out a bunch of secular graphic literature for the kiddie set from the library recently. Several friends mentioned they are struggling to get their kids excited about reading, and I committed to checking some out to check if they are "kosher" for the consumption of frum kids.
So far, I have found some options. Two titles from Toon Books (Candlewick Press's new Easy to Read comic line), Zig and Wikki in Something Ate My Homework, and Mo and Jo Fighting Together Forever are clean, nicely illustrated, and silly enough for first through fourth graders. My kids really, really liked them. I should add that my new reader, who usually refuses to do the reading himself, was really motivated to do so with this book. Amazing. He's virtually begging for me to find more Toon Books at the library.
I enjoyed Patrick Atangan's The Yellow Jar more myself. However, it's more sophisticated and definitely tailored for older kids, at least 5th grade.
Still trying to finish the stack from the library. Next up, Lunch Lady and the Summer Camp Shakedown.