Gwen stepped outside and cracked her knuckles, still grinning in the same malevolent way.
"Hey, did you see that? I totally slaughtered him!" Ben said proudly, smiling, oblivious to Gwen's expression.
"Mmmhmm," Gwen replied. "You did."
Ben then noticed her vacant stare. He opened his mouth to say something, but Gwen beat him to it.
"Say, come over here. I'd like to show you something you'll find very interesting." She remarked boldly.
"Um, alright," Ben said.

/He has no idea what he's in for.../ Gwen thought to herself contently. She waited until Ben was no more than an arm's length away, and then she pounced.

She activated the spell, and then quite animalistically, she began to shove her cousin's head into her mouth. She was amazed at how stretchy her cheeks were and at how strong she had become. Continuing to force Ben into her jaws, he started to struggle, flailing his arms about and kicking her. She hardly felt it. He yelled out for help, but his head now being inside Gwen's mouth, his cries were too muffled to be heard.
She proceeded to gulp down her struggling victim, snakelike in her swallowing, and giggled as Ben's head slid down her throat. She was now up to his waist, and he was still throwing his legs about. Gwen reached out a hand, and grabbed both of his legs tight. She then used her hand to push the rest of Ben's body into her maw, and gulped, transferring the bulge in her cheeks to her asophagus.
She moaned as the strain on her throat intensified, until, with a final plop, Ben landed in Gwen's stomach, curled up into a tight ball.
Gwen's belly was now swollen beyond belief. She rubbed it contently, and her belt buckle snapped.
Ben began to yell from within her churning gut.
"GWEN! You're a NUTCASE! What on earth did you do that for? Let me out, or I'll..."
All went quiet for a moment before Gwen's stomach bulge became even larger, and the sheer weight of her stomach caused her to topple over. She knew exactly what he had done...what an idiot he was, thinking he could escape by turning into Cannonball.
"Hah...some hero you are," She said cockily.

At this point, Gwen remembered a second part of the spell.
It stated that upon eating her first victim and growing, should she desire it, she would turn into a bipedial animal version of herself, what some would call a 'furry'.
She felt a strange tingling as she slowly began to grow. She decided...