Barney, Mr. Thomas, and The Alligator Creature

Eleven-year-old Barney Gile turns into an uncontrollable alligator creature whenever he gets too upset. Ever since he was rescued from a swamp by Mr. Thomas, a kind inventor who fears love, Barney has been happy. Happy joining Mr. Thomas on crazy adventures to different worlds and making strange machines. Barney has never seen a reason to remember his past. Until he finds out the horrible truth.
Barney and Mr. Thomas meet the couple who created Barney, and he isn't their only project. Amber and Ivan are sweet talkers, able to convince the other hybrid children into believing they belong to them. Barney worries they might even entrance him to live with them.
With the help of a rat who is turning into a boy and inventions like a mind-jumper, Barney and Mr. Thomas are going on adventures while figuring out how to free the rest of the hybrids. But it seems like the hybrid children don't want to be saved. They are content with their lives lacking real families. How is Barney supposed to convince them Amber and Ivan are the unloving ones when the couple is constantly reminding Barney that Mr. Thomas is scared to love?