Who's Your Mummy? is the sixth book in the Goosebumps HorrorLand book series. It was preceded by Dr. Maniac vs. Robby Schwartz and followed by My Friends Call Me Monster.
It was released in January 2009 and is exactly 133 pages long.
Abby Martin is very worried about Granny Vee. She's sick and isin't getting well. So Granny Vee sends Abby and her little brother Peter Martin to their Uncle Jonathan's house. They notice that his house looks familiar to an Egyptian tomb. Are any mummies in his house?
The reader would not have known who Michael Munroe was, as he wasn't officially introduced until the next book.