Who named the turtle in Judy Blume's Tales of a Fourth Grade Nothing?

In the opening chapter of Judy Blume's Tales of a Fourth Grade Nothing, the main character Peter himself names the turtle Dribble.

Peter won Dribble as a prize at the birthday party of Jimmy Fargo, Peter's best friend. All the other boys at the party had been given "goldfish in little plastic bags" as party favors  (p. 4). Peter had been the only guest who did not get a goldfish, which disappointed him at first. However, towards the end of the party, Mrs. Fargo announced that "Peter Warren Hatcher is the big winner!" of the jelly bean guessing contest (p. 4). Peter had guessed that there were 348 jelly beans in a jar, which was the closest guess to the actual number, 423. As a prize, Jimmy had handed Peter a glass bowl filled with rocks and water; upon the biggest rock, a "tiny green turtle was sleeping" (p. 4). Peter, the first-person narrator of the story, informs his reader that he named his turtle Dribble while carrying his bowl along the street, walking home from Jimmy's birthday party.

While we are never told exactly why Peter chooses the name Dribble, the reader can presume he felt it was the perfect name for a turtle since the act of dribbling can be associated with fluid whereas turtles, like Dribble, live in water.