Giant black Snake in the library of time

"i was in this giant library looking for a book on how to fix a clock, even though i don't even own a clock. the carpet was really plush and green, but every time i walked down an aisle the bookshelves kept getting taller and leaning inward. i dropped my pencil and reached under one of the wooden study desks to grab it, and that's when i saw it tucked in the shadows. it was this long black snake, completely pitch dark like it was absorbing the light around it, just coiled quietly next to the leg of the desk. it was way bigger than any snake should be, thick as an oil drum, and its skin had this slick, glossy sheen. i went totally stiff. i knew i needed to run or back away, but my eyes were just locked on it. then it slowly uncoiled a few inches, making this dry rustling sound against the carpet, and turned its head directly toward me. it didn't have any real expression, just these completely flat, glossy black eyes. then all of a sudden the library was gone and i was sitting in the backseat of my dad's old car in total silence, but i could still feel it right under my feet on the floorboards, waiting to move."