My pen ran out of ink and an ink fairy in the shape of a squid appeared. He said if I let him eat my dinner of shrimp he'd help me out by giving me some ink. The deal smelled kind of fishy, but I needed to finish my homework. So we did it squid pro quo.
A proctologist is about to write a something on his patient's notes but when he goes to take his pen out of his pocket he realizes it's actually his thermometer that's there.