Her eyes met yours and you felt locked by her gaze even as you felt your body began to shift and change into a bestial form.
You could feel yourself begin to grow, your muscles and bones aching and creaking as your spine curved and forced you forward onto hands and knees as Magritte skipped backwards giggling. You could feel your shoes split as your feet lengthened and your toenails curved and erupted into sharp claws that gouged the earth of the forest floor beneath you. Your thighs swelled with corded muscle, seams of your jeans snapping and tearing away revealing the skin beneath, growing dark with hair. A lancing pain through your rear as a tail erupted from above your ass, bursting free in shreds of cloth from your boxers and curling between your legs in fear and pain as your change progressed.
Your hands before your eyes you saw grow into canine paws the size of hub caps, claws kneading at the dirt as you shuddered from the power of the change. You were on all fours and you could feel your shredded clothes all tumbling away from your massive muscled form, replaced with rapidly sprouting black fur. You could feel something heavy, pendulous between your legs and as you shuddered and glanced down you glimpsed your cock swelling massively, foreskin regrowing and covered with fur even as what was contained by that sheath grew knotted and red. Your vision blurred, growing sharper but colors fading somewhat, muted, even as you felt your face contorting.
Your jaw cracked and creaked as it pushed outwards, teeth growing wickedly sharp, set amidst black gums. You felt rather than saw your triangular ears flicking above your head as your muzzle came to a rest, your black nose sniffling as you whimpered. You could smell the richness of the earth, the wild animals all around, the power flowing through Magritte, and the sweet flesh that contained that power, that responded to it, that desired it.
You slumped, defeated, onto the forest floor, a wolf the size of a draft horse covered in night-black fur. Your whimper an admission of Magritte's power, and your condition as she stepped forward and placed a hand on your massive head, stroking gently.
"There there Gloom. No need to fear. You belong to Magritte now. And she has a task for you..."
Your eyes met hers as she smiled, "I need you to..."