The dragon raises an eyebrow as you approach its rear foot. With a slow, heavy crunch, it sits down, lifting one rear claw for you to examine closely. The massive limb is taller than you are. It is vaguely reptilian, with three long toes on the top, and one shorter, more thumblike claw near the heel. Each of them is tipped by a jagged obsidian-like claw the size of a greatsword. While the top of the creature's foot is covered in hard blue scales, each of them as large as a buckler, the underside is softer and smooth, and its color is a light yellowish cream.
You move closer, reaching out to touch the flesh. It is soft and slightly ridged, compressing under your touch like a heavy mattress. This close, the scent of the sweaty unwashed dragon flesh is overpowering. Beads of glistening sweat clean to the soft sole of the foot, and they smell enticing and powerful. Touching one marble-sized bead, it sticks to your skin like slime, thick and viscous. You raise it to your nose, breathing deeply.
The scent is unlike anything else you have smelled before. Something about it is dirty and primal, and it is unmistakably sweat. It carries a heavy undertone of filthy, hot gym lockers that should be disgusting. But layered on top is a soporific incense-like scent, reminiscent of the smell of an extinguished candle. At the back of your nose, there is a final sharp scent of exotic spices, all of it combining to create a musk that you would roll around in if you could.
The dragon wiggles his toes slightly as you touch his foot, clearly a little ticklish. You press your hands against the flesh, feeling it gently. It is soft at first, but beneath you can feel the hard, hot form of powerful muscle. The flesh is exuding heat like a radiator, and it makes you sweat so close to it.
The dragon is grinning, clearly enjoying your interest.
"Do you like what you see, human?"
Gritting your teeth, ashamed of your arousal, you nod, which makes him laugh wickedly.
"Ah, you wish to partake of a taste of my strong, sweaty paws? Very well, you shall have a lifetime of them."
The dragon stands over you, his huge, warm body casting a shadow over the cave, and slowly lowers his back foot onto you, pressing you down onto the floor. You lie on your belly as he presses his foot onto your back, the damp, sweaty skin covering you as he pushes down harder and harder. The strong, musky scent of his foot stings your nose, and you groan at the pressure, your cock becoming hard, stretching and oozing until finally, you cum furiously over the floor and the dragon forces his foot to the ground with a sudden crunch.
After a moment, you open your eyes, shocked to still be aware. You were sure that you had felt your body being crushed under the dragon's paw. You felt bigger, and slower somehow. Stronger, too. The stink of the dragon's foot smelled a great deal stronger now, and you could even taste it in your mouth. It seemed to be surrounding you completely.
In fact, that is not the only strange sensation you are feeling. Your body seemed to no longer have a bottom, instead a sensation of your awareness rising upwards and slowly fading into warmth. You could feel an intense, powerful pumping throbbing through your body, a heartbeat totally unfamiliar to your own.
Forcing yourself to focus, you look around. Moving your neck feels a little difficult, but you can look up and see the dragon's underbelly above you, his powerful muscles shifting as he moves. In front of you, some distance away, are the shapes of his forepaws holding him up. Looking left, you see a huge blue claw-tipped toe. You try to raise your left arm and move, but are shocked as the toe raises in the air, then goes back down.
Looking right, you see a similar toe. With sinking dread, you raise your right arm and see that one rise too. You are a dragon's foot!
Your shock is quickly washed away, however, when the dragon curls up, pulling you towards him, and slowly begins licking your soles and nuzzling your toes, the feeling like a massage, sexual and wonderful. Instantly you fall in love with your master, and resolve to be a good foot for him.
The transformation is permanent, leaving you as only the left back foot of a huge dragon. Without a brain, your mind slowly fades and crumbles, and you forget ever being human, enjoying only the pleasurable feeling of mud beneath you and sweat around you. Over the years the dragon slowly regains control of his foot, leaving you helpless as he manipulates your body without your control, and eventually he forgets that a human ever invaded his cave. You are left trapped as an observer in a dragon's foot, yet without memories or a mind of your own, it does not bother you, and you merely experience the contentment of an animal as you are carried around by your master's leg, forever.