"Kids, Aunt Louise is coming tomorrow," Mom told Daniel and me the next morning. "So I want you both to clean up your rooms after school today."

"Aunt Louise is coming?" I asked. "Great!"

Aunt Louise is my favorite aunt. Even though she's a grown-up, she's completely cool.

She wears long, flowery dresses and drives a bright yellow convertible.

And Aunt Louise blows the biggest bubble gum bubbles! And she knows a lot of really funny jokes.

Mom says Aunt Louise has her head in the clouds. I guess that means she has a wild imagination. I don't know about that, but she does know a lot about things like astrology and tarot cards.

And, maybe—about Grools.

That night, after I cleaned my room and before I went to bed, I said a special good night to the Grool.

"My aunt is coming tomorrow and she's going to help me get rid of you forever," I whispered. It stared up at me, breathing softly.

After school the next afternoon, Daniel and I turned the corner onto our block. And we saw Aunt Louise's yellow convertible in the driveway. We ran the rest of the way home.

"Hey—what's up?" Aunt Louise called as we burst into the house. A floppy yellow straw hat covered her black curly hair.

Before Daniel could get to her, I threw my arms around Aunt Louise and whispered in her ear, "Come upstairs with me. Now. It's super-important."

My aunt pulled off her hat and set it on my head. She admired me in the hat. "Super-important?" she asked.

"Yes," I whispered, grabbing her hand and tugging her toward the stairs. "Have you ever heard of a Grool?" I asked.

"A Grool? Hmmm. I'll have to think about that one for a minute," she replied thoughtfully. "No, I don't think so. What is a Grool?"

"Well," I explained, "Daniel found a picture in an encyclopedia. And the book said it was an ancient, mythical creature...."

"Well, if it's mythical, honey, that means it doesn't exist," Aunt Louise interrupted.

"But it's not mythical!" I cried impatiently. "I should know because I have one. And it causes trouble, lots of trouble."

Aunt Louise followed me to my room.

"Have you ever heard of a Lanx?" I asked. She shook her head.

"That's another creature in that encyclopedia. It looks like a potato, but it has a mouth full of sharp teeth."

"Good heavens. It sounds disgusting!" Aunt Louise exclaimed. "But tell me about this... Grool. What does it look like?"

"Here. I'll show you," I said. I pulled her into my room.

I pointed at the gerbil cage. The Grool squatted in the corner.

Aunt Louise walked up to the cage. "So you're a Grool," she said, leaning down. She reached over to pick it up.

"Wait," I cried. "Maybe you shouldn't touch it." But I was too late.