The pressure begins to feel like something stabbing into the back of his pants. He looks back and there's something long and thin, jutting out from where his tailbone is. The pants are stretched tight and seem to be pulling the thing into an arch. Finally Paul feels a shift down there, as the long thing relaxes and lets the pants pull it straight down. For a moment it seemed as if he could really feel the cloth brushing past the thing.
"What is that?!" Paul thinks as he removes his suddenly uncomfortable clothing. He gasps.
Paul sees that he now has a foot-long, narrow appendage ending in a point. It's smooth, covered with his regular skin as he reaches out a hand to grab it.
"I've got a tail," he thinks as his tail feels his fingers surrounding it.
He bends his tail with his hands a little bit, but it really hurts to bend it very far! He lets go of his tail and tries to move it. The tail wags bag and forth.
"I have a tail!" he screams, and his new tail jumps. But what kind?
Then short black fur starts to sprout out of the tail, and he recognizes it. His tail looks like that of a black labrador. He wags his tail voluntarily again, and it definitely looks doggish.
Then Paul feels a swelling in his ears. Reaching up to touch them, he feels that they have lengthened and widened into flaps which have flopped over. Discovering a new muscle, Paul discovers that he can perk his new ears up or let them flop down.
"What is going on?" he wonders. "Am I really turning into a dog?"