Canon, 'Falstaff, lass dich sehen!', WoO 184 (mp3)
In the circle of Beethoven friends, Falstaff was the nickname for violinist Ignaz Schuppanzigh. The nick refers to the character Falstaff from several Shakespeare plays, who is extremely fat. And as you can see, our Schuppanzigh was not the skinniest of men either.
He was the butt of many jokes by Beethoven, some of which were quite offensive. An innocent example would be : Schuppanzigh is dead scared of narrow alleys (ie., afraid that he will get stuck), and Beethoven loved to hurl insults at him in the form of musical jokes and canons, such as 'Lob auf den Dicken' (WoO 100) and 'Esel aller Esel' (Hess 277). That inspite of this abuse Schuppanzigh remained loyal to Beethoven his entire life, indicates a character that did not know of any malignancy.
The current canon is an exception in that it does not contain any insults : 'Falstafferel, lass dich sehen!' [='Little Falstaff, show yourself!'] is just a (more or less) polite command by Beethoven to come over and discuss certain matters.