In the excerpt from "Pecos Bill and the Bear Lake Monster," the possessive nouns that indicate ownership are 'Bill's head,' 'snake's mouth,' and 'monster's neck.'
The exercise provided is about identifying possessive nouns within the given excerpts. A possessive noun shows ownership, a relationship or that something belongs to someone or something else. In English, possessive nouns are often formed by adding an apostrophe and an 's' ('s) to the end of a noun, although there are exceptions, particularly with plural nouns.
In the provided excerpt from "Pecos Bill and the Bear Lake Monster," the possessive nouns are "Bill's head," "snake's mouth," and "monster's neck." These examples indicate ownership: the waves are crashing over Bill's (belonging to Bill) head, the size comparison to the snake's (belonging to the snake) mouth, and Pecos Bill slipping a loop into the monster's (belonging to the monster) mouth.