Dreki: My Icelandic Dragon — Mary Logue

A boy, his grandfather, and a baby dragon set off on an international adventure that takes them from the Midwest to Iceland in this children's fantasy novel perfect for fans of When You Trap a Tiger and How to Train Your Dragon. 

Johan is off to visit his Grandpa Siggy -- a charismatic, impetuous Icelander with a big secret: He took a dragon egg with him when he immigrated to America. As fate would have it, Dreki hatched just a few hours after Johan was born, magically linking the two. But Dreki was kept hidden.
 
Now, many years later, the time has come for Dreki to journey home and for Johan to discover his ancestry through a life-changing trip to Iceland. But the clock is ticking, as both Siggy's and Dreki's health are in jeopardy. This cross-cultural coming-of-age story explores aspects of Icelandic folklore while dealing sensitively with the themes of aging, generational memory, and returning home.