~ Sitzet ihr fröhlich beim Bier ~
The reference here to the cat beast is the beer drinkers symbol of a hangover. The 2-liter stein is marked with the Reinhold Merkelbach logo and "453 E", ca. 1900.
Sitzet ihr fröhlich beim Bier,
denkt auch an's Katerthier!
Sit yourself happily with a beer,
(but) think also about the cat beast!
Translation: Roy De Selms
Photo credit: Unknown