Some background on this comic:

Transcript (commentary):

I was playing around with the caption on this cartoon before it suddenly dawned on me that it really didn't need one. The story's told by just the scene of a legless cat in a store with a piranha residing nearby in a fishbowl. I also decided to put wooden legs on the cat in the final version, not wanting to make cat fanciers more upset than necessary.

Aquarists, however, loved it.

Transcript (sketch):

Boy, there's no love-loss there…That cat never has figured out exactly what a pirahna is." forgiven that pirahna."