The German beer whose name is a pun.
In the 14th century the northern town of Einbeck, Germany was producing some great tasting beer with higher alcohol content than typical lagers. The beer was brewed by individual households (in citizen brew houses) but the town owned all of the beer making equipment and hired hundreds of master brewers. This helped maintain a consistently high-quality product throughout town. As Einbeck joined the Hanseatic League they exported their beer around Europe and the popularity of their beer grew. In 1521 Martin Luther said that “The best drink anyone knows is called Einbecker beer” and later served it at his wedding.
In the early 17th century the master brewer Elias Pichler was lured down from Einbeck to Munich by Duke Maximilian to help the Bavarians make the Einbeck beer, or “Ainpöckisch bier”. The Bavarians changed the name a bit and with their southern pronunciation Ainpöckisch bier became “Oanpock bier” which was eventually shortened to just “Bock bier”. Soon the Einbeck style of beer was known by the name created by the brewers in the south.
As the centuries progressed bock beer posters, signs, and bottle labels tended to have a common visual motif – the image of a goat. No other style of beer has had such a consistently universal visual element. Goats have been used as imagery for bock beer across breweries, across time, and across countries. The reason is that “bock” in German means “male goat” (among other things). So Einbeck could be “ein bock” or “a goat”. Goats selling bock beer is a visual pun. It’s a multi-century dad joke.
Added info: there are different styles of bock beer including Maibock which is a seasonal beer made in the Spring for the month of May (hence the name, “May bock”). The Sly Fox Brewery in Pennsylvania hosts an annual goat race where each year’s Maibock is named for the winning goat.
Also Doppelbock (“double bock”) is an even stronger bock brewed for Lent and the strong beer season.