As Ben stared at his fully bovine hindquarters, he noticed a patch of green on the carpet under his hooves. That puzzled him, since the carpet was blue, but then another wave of pain rippled through his chest and down his arms. He shuddered and tried to cry out, but his throat constricted and it felt like someone was trying to pull his head off. When the ache faded he was panting, feeling swollen and heavy. He looked around in confusion. The room around him was smaller and curiously translucent, allowing him to see the rolling fields and cattle outside. Except they lived in the city, and there should just be more houses. And when he looked down, he saw forehooves instead of hands, with thick grass growing up around them.
Sudden realization hit, and Ben looked over at the nearly invisible photo album. The field now getting clearer was the same one the photo had been taken in, and Ben the boy was changing into Ben the Highland Bull. That seemed to trigger the final stage of the transformation, and the former boy bellowed as his head swelled out and massive horns emerged from his skull. The ghostly image of the house faded out completely, replaced by the rolling hills of a Scottish pasture. Ben blinked, bewildered by the shift of place and form... and time? There was a young man checking over a Highland cow close by, and when he turned back to Ben it was obviously his Grandfather from the photograph. The man looked startled, then grinned. "Sneaking up on me, eh laddie? I thought ye was locked up in the paddock! No matter. This lassie is ready for your attentions!"
Ben bellowed, trying to explain to his grandfather, but not only could he make no human sounds, the cow's scent was washing over him and calling to growing bovine instincts. His rather impressive bull's sexual parts were responding, and it would take all of Ben's willpower to resist. The former boy took a hesitant step towards the cow, who raised her tail and urinated. Instead of being disgusted, Ben's nostril's flared as he drank in the rich aroma that told him the female was in heat and in need. Desire filled his mind, and Ben knew it wasn't all the bull's. He wanted to explore this powerful new body, to see what it felt like to be such a massive and potent male. Another hesitant step - had this been a subconscious wish? Some long-buried jealousy of the bull? That seemed ridiculous - Ben didn't want to spend the rest of his life as a dumb animal, even one used as a breeder. But maybe just once?