Hat man phenomenon. It's a very common sleep deprivation/sleep paralysis hallucination. It's actually pretty interesting, since it's only been common for a few decades, likely due to movies involving tall scary men with hats.
Madness string 111266
As of this writing, the phrase 'I'd like a cup of spiders' gives exactly one result in a Google search, compared to 3.75 million results for 'I'd like a cup of coffee'.