Funny and fast-paced, Wally's one of those books that boys will enjoy maybe just a little bit more than girls - and there aren't enough of those books.
Michael's mother doesn't think that "that Wiggins boy" is someone Michael should spend time with. This is all due to an incident involving a horned toad. That makes it unlikely that Michael's mom is going to be thrilled when Michael brings home a chuckwalla named Wally. Billy Wiggins is going on vacation and he needs some lizard-sitters. He's chosen Michael to take care of Wally and Michael is thrilled. All he has to do is hide the lizard from his parents for several weeks.
Michael's brother Roger is more than happy to help with the plan. They set up a box in Michael's closet and arrange for Wally's well-being. All goes smoothly for weeks, until just a few days before Billy is due home. Suddenly, Michael's parents start talking about moving, showing the house to strangers. The kids aren't happy about this at all, but they've got more immediate problems - Wally's missing! How can they concentrate on stopping their parents from selling their house when they're trying to find the lizard before its owner comes home?
The book dates itself a little - a microwave is a new thing that the kids aren't familiar with and a phone number begins with two letters - but other than those two details, the story is almost thoroughly timeless. Every kid who's ever tried to pull the wool over their parents' eyes, or just wished they could, will find themselves relating to Michael and Roger.
Lots of fun with a very believable family and, although wild and wacky, a quite believable adventure including a chuckwalla, 2 brothers, a mom who does not want her roses fed to a lizard and a lady who would rather have a chihuahua than a child.