Thomas's

I am Thomas's cousin.

Source: tatoeba (5165235)

Mrs. Thomas's father was pursued home one night by a lamb of fire with its head cut off hanging by a strip of skin. He said he knew it was the spirit of his brother and that it was a warning he would die within nine days.

Source: tatoeba (5831774)

You're one of Thomas's students, aren't you?

Source: tatoeba (8576763)

Isn't this Thomas's?

Source: tatoeba (8908604)