Did Tip's creation, Jack Pumpkinhead, serve its purpose in the novel, The Marvelous Land of Oz?

No, Mombi was not frightened.

So intent was Mombi on the treasures she had gained that when she turned the bend in the road and caught a glimpse of the man, she merely nodded and said:

“Good evening, sir.”

But, a moment after, noting that the person did not move or reply, she cast a shrewd glance into his face and discovered his pumpkin head elaborately carved by Tip’s jack-knife.

“Heh!” ejaculated Mombi, giving a sort of grunt; “that rascally boy has been playing tricks again! Very good! ve—ry good! I’ll beat him black-and-blue for trying to scare me in this fashion!”