The song begins with Ratigan mentioning his earlier crimes, and that his current plan will be even more wicked than before. It then changes to his henchmen singing their admiration of their evil leader before switching to Ratigan lamenting over Basil's constant interference with his plans, before wickedly claiming that not even Basil can stand in his way this time. The henchmen sing their praises again, but the song is interrupted when Bartholomew, a mouse who had made himself extremely drunk throughout the song, loudly calls Ratigan the 'world's greatest rat'. Enraged, Ratigan flings the henchman out his lair and has him devoured by Felicia. Once Bartholomew has been consumed, the henchmen resume their singing (mostly out of fear due to Ratigan giving the implied threat of feeding them to Felicia next if they didn't), and the song ends with them smashing their wine glasses together as Ratigan displays his signature grin.
Ratigan: From the brain that brought you the Big Ben Caper
The head that made headlines in every newspaper
And wonderous things like the Tower Bridge Job
That cunning display that made London a sob
Now comes the real Tour de Force
Tricky and wicked of course
My earlier crimes were fine for their times
But now that I'm at it again
An even grimmer plot has been simmering
In my great criminal brain
Chorus: Even meaner? You mean it?
Worse than the widows and orphans you drowned?
You're the best of the worst around
The rest fall behind
The world's greatest criminal mind!
Ratigan: Thank you. But it hasn't all been
champagne and caviar. I've had my share of
adversity, thanks to that miserable, second rate
detective, Basil of Baker Street. For years that
insufferable pipsqeek has interfered with my plans.
I haven't had a moments piece of mind. But, all
that's in the past! This time, nothing, not even
Basil, can stand in my way! All will bow before
Chorus: Oh, Ratigan
You're tops and that's that
To Ratigan Bartholomew: To Ratigan the world's greatest rat!
(Song temporally stops)
Chorus: Even louder
We'll shout it!
No one can doubt what we know you can do
You're more evil that even you
You're one of a kind
The world's greates criminal mind!!!
There was a deleted lyric that expanded a bit on the London Bridge Job: Ratigan had thrown several civilian Mice into the Thames River, and shot any that attempted to surface. It was presumably cut because of the dark and family-unfriendly nature of the lyric.
Interestingly, the part that says "The Widows and Orphans you drowned" may be the same crime.
Coincidentally, the name of the song was previously used with the character Egghead in the 1960s Batman show, who was portrayed by Ratigan's voice actor, Vincent Price.
On February 28, 2018, TimzUneeverse uploaded a bait-and-switch video parodying the song, titled "The Big Ben Caper", with most of the lines modified to say "Big Ben Caper", and featuring lines from Tsushima Yoshiko from the anime series Love Live! Sunshine!!. (link)
"From the brain that brought you the Big Ben Caper"
Ratigan coughing up his wine after hearing Bartholomew call him a rat