Yes, delicious oysters. Back when Samuel Johnson's cat Hodge was alive, oysters were so plentiful that poor folks ate them regularly; think of that. And in an age where cats were fair game for any mean sport, Johnson loved his cat so much that he himself went to buy Hodge's oysters, saying his servant Francis might feel humiliated by the task. Though Johnson had other cats, Hodge was the one closest to his heart.
In 1778, Johnson's friend Percival Stockdale wrote An Elegy on the Death of Dr Johnson's Favourite Cat, which manages to be heartfelt and tongue in cheek at the same time, and is also the only clue we ever got as to Hodge's color - he was black. Here's a snippet:
And shall not Hodge's memory claim
Of innocence the candid fame;
Shall not his worth a poem fill,
Who never thought, nor uttered ill;
Who by his manner when caressed
Warmly his gratitude expressed;
And never failed his thanks to purr
Whene'er he stroaked his sable furr?
(See poem as a whole in this very cool blog post.)
In 1997 Hodge got his own statue in front of the house he and Johnson had shared. Copyright forbids me to paste it here, but I'll send you to this great photo. And moggies.co.uk has a fine page on Hodge.