Secrets of Dripping Fang, Book One: The Onts -- Dan Greenburg

Judging from the first book, I'd say the series is a cross between Lemony Snicket and The Spiderwick Chronicles, with a reading level somewhere between the two.  (Closer to Spiderwick.)

Like the Baudelaire children, Wally and Cheyenne just can't win:

The year they turned seven had been a bad year for the Shluffmuffin twins.  The week of October 12 was particularly awful.

On Monday while visiting the Cincinnati circus, their father, Sheldon Shluffmuffin, a slender man, fell through the seat of a Porta Potti and drowned.

On Tuesday at the petting zoo, where she had taken the twins to get their minds off their father's death, their mother, Sharon Shluffmuffin, was overpowered and smothered by a gang of angry bunnies.

I loved it.  The illustrations were fantastic, it was super-gross (the poor Shluffmuffin twins are adopted by a pair of giant ants who want to use Wally's stinky feet and Cheyenne's over-abundance of snot to take over the world), and it was funny without being overly self-aware:

On the other side of the highway was Dripping Fang Forest.  The forest was so thick and so dark it seemed to swallow up light like a black hole.

Next to the sign that read DRIPPING FANG FOREST was a smaller sign.  It read:  PRIVATE PROPERTY.  KEEP OUT.  THIS MEANS YOU.  TRESPASSERS WILL BE...

The word PROSECUTED had been crossed out and somebody had written SHOT above it.  The word SHOT had been crossed out, and somebody had written TORN APART BY WOLVES about that.

"I don't get a good feeling about this place," said Wally.

The twins also run into a glowing ten-foot-long slug that loves to eat orphan feet, a professorly type who is married to a huge spider named Shirley, and a pack of very polite, ravenous man-eating wolves.  (The leader is named Fred.)

Super highly recommended.  Loved it.  Can't wait to read more.