Don't try to fathom its motivation. Wepwawet's just a right proper bastard that has been kicking around down through the eons, getting a few jollies every few centuries when he decides to come out and screw with an occasional human life. Once a minor deity in a forgotten echelon of more obscure Egyptian gods, he's outlasted most of that horde that came charging from the delta of the Nile in the cradle of the planet's first civilizations. He would like to make a wager on Jared's odds of retaining his humanity, but there's no other entity in the near cosmos available to accept the bet. It gets rather lonely and, not having really communicated with another being for hundreds of years, Wepwawet's quite insane. For the record, he would bet against the young human male. He'll put forth a valiant struggle, no doubt, but in the end they always go down into the muck.
The next morning, still spooked by the strange dream, Jared showered and removed the offensive odor of his over-active sweat glands from his skin. Stepping out of the shower and fastening a towel around his waist, he picked up his toothbrush and gazed into the mirror as he brushed his teeth.
He jumped back like a true believer who had seen the devil when that dog-like face of the creature from his dream materialized in the mirror in place of his own reflection.
"You appear nervous, human," the snout opened and closed on the dog-like face.
"You...you're real," Jared stammered, his arms hanging at his sides, toothbrush gripped tightly in one hand, lathered foam of the toothpaste visible in his open mouth.
"Rabid?" The deity wondered aloud, staring at the human's foaming at the mouth.
"No!" Jared retorted. "I'm brushing my damn teeth. Why the hell do you keep bothering me?"
His hand visibly trembling as he tried to appear unmoved by the entity's presence, Jared turned on the water in the sink and filled his glass. He rinsed his mouth, spit into the sink, and looked into the mirror again. The mirror's surface showed him only his own reflection. He started to take a deep, relieved breath when he saw the full form of Wepwawet integrate itself behind him, the mirror capturing both their reflections.
"What an odd way for a dog to drink," Wepwawet remarked.
Jared placed the glass on the countertop of the sink, producing a jarring clank. "You're not real," he said. "You can't be real!"
A chilling blast of icy laughter reverberated in his ears and brain. "I'm quite real, you ludicrous beastling," came the contemptuous retort.
"Go away!" Jared exclaimed.
"Do you feel yourself this morning?"
"Of course, I do," Jared answered without hesitation. It was true. So far, no doggy tendencies had manifested in any of his behavior since waking.
"Are you sure?" The being's question got into his brain and sounded like an echo along damp corridors.
Jared felt a sudden, intense thirst.
"What's wrong?" Wepwawet inquired.
He turned to the sink for a glass of water, but the entity intervened. "Not that way!"
Jared felt himself sinking onto his hands and knees. "Thirsty? Drink all you want!"
He crawled forward toward the porcelain bowl of the toilet with its pale blue infusion of name-brand toilet freshener steadily replenished by his mother. No! He couldn't drink from the toilet!
He crawled closer, relegated to hands and knees, and stared at the cool, refreshing water in the bowl.
"Drink!"
He whimpered and felt his towel fall away from his waist, leaving him naked and feeling even more vulnerable in the palpably malevolent presence of Wepwawet.
He warred against it, but his thirst felt too intense, like he had eaten a bucket of sand. He plunged his entire head into the bowl and guzzled the water down his throat as Wepwawet's loud laughter gradually grew fainter.
Jared was still drinking from the toilet bowl when the door opened and Kevin walked into the room.
"Jared!" His kid brother exclaimed. "What are you doing?"
Blue-tinted water dripping from his chin and his entire face aflame from shame, Jared looked up at his mortified younger brother.