look like the cat that swallowed the canary To look smug; to appear very self-satisfied or pleased. This self-evident expression has been in use since 1871.

resting on one’s laurels To be content with one’s present or past honors, accomplishments, or prestige. The laurels in this expression have long been a symbol of excellence or success in one’s field of endeavor. Resting indicates self-satisfaction and complacency with the implication that no further efforts will be expended to acquire additional figurative laurels. It is interesting to note that ancient philosophers and poets sometimes kept laurel leaves under their pillows for inspiration, a concept almost totally opposite to the phrase’s contemporary meaning.

snug as a bug in a rug Extremely comfortable and content. This common expression of obvious derivation was purportedly used by Benjamin Franklin in 1772. The phrase enjoys frequent use in the United States.