Zindel, Paul. Loch. (1994)
Loch and his sister Zaidee are with their father at Lake Alban. He is working for the evil Mr. Cavenger, who is trying to find Loch Ness type creatures to "study". There are several in the lake; Rogue, who is the biggest and has killed a couple of people, and a smaller one. Then, Loch finds a baby pleiosaur he calls Wee Beastie and feeds ham sandwiches. Even though the older versions like to chomp people in half, Loch feels comfortable frolicking with the small one. When it becomes clear that Cavenger is not going to keep the animals alive, it's up to Loch, Zaidee, and their friend Sarah to safe guard the animals.
Strengths: Again, a gore fest, but not until page 46. There are a few innocent victims, but in general, pleiosaurs prefer the taste of bad guys.
Weaknesses: Out of print! The copy I was reading had pages falling out of it. Perma Bound seems to have all of these available, although for Loch it says "edition not yet published".
Smith, Andrew. The Marbury Lens.
I was so excited to read this one, based on the information from the publisher: "After being kidnapped and barely escaping, sixteen-year-old Jack goes to London with his best friend Connor, where someone gives him a pair of glasses that send him to an alternate universe where war is raging, he is responsible for the survival of two younger boys, and Connor is trying to kill them all." that I saved it for my Sunday evening reading. Big disappointment. It was an obscenity fest, and also included a party with rampant drinking and undesirable behavior. Sigh. Maybe for high school students, but this was certainly not something I will buy for middle school.