When relsqui was coding FlyingFerret, there was an insidious bug involving array indices that resulted in the bot being unable to say anything except "Bananas!"
04:04 <xkcd> flyingferret: hi 04:05 <flyingferret> Bananas! 04:05 <relsqui> see? 04:05 <flyingferret> Bananas! 04:05 <xkcd> This shit is ... 04:05 <flyingferret> Bananas! 04:06 <relsqui> and this is why we have a test channel 04:06 <flyingferret> Bananas! 04:11 <relsqui> apples or oranges? 04:11 <flyingferret> Bananas!
It just got funnier and funnier as the night wore on and the damn bot kept cheerfully announcing 'Bananas!'. It's hard to debug through tears of laughter.
They eventually fixed it, but to commemorate the bug Bucket was trained to randomly reply "Bananas!" every now and then.