I'm looking for a word, not necessarily a direct “reverse dictionary” sort of word that has the definition above, but even a creative word that can describe, label, or represent that sort of person with just the one word. Having a slightly negative connotation is an added bonus, and a balance between negativity and positivity is also fine.
Again, the label sought is to describe, stand for, or attach to a wise and studious or academic person, but who is also frail and ghastly.