Cogwork Librarian

Protection from Rats.
When you would draw a card and it is not your
draw phase, you may Sacrifice Cogwork
Librarian. If you do, search the top 15 cards of
your library. Put one card from among them
in your hand. Put the rest back on top of your
library. Shuffle your Library.
"Fools trust Demons for knowledge. A good library,
cataloged and mechanized, is far less perilous. It can
handle the vermin and reliably retrieve a needed tome
or scroll." - Muzzio, Visionary Architect