This is book number 2 in the Nathaniel Fludd, Beastologist series.
"Picking up immediately where Flight of the Phoenix (2009) finished, Nathaniel Fludd, Aunt Phil, and the gremlin Greasel pursue an escaped Basilisk, the highly dangerous king of the Serpents...
Familiarity with Nathaniel's previous adventure is helpful though not necessary, and fans can look forward to a return to Batting-at-the-Flies as the trio investigates the disappearance of Nathaniel's parents in the forthcoming volume."--Booklist —