That would be the German pronounciation for "Lump," which in that language means "rascal." Lump was a dachshund belonging to Picasso, acquired in 1957, and much beloved. At least I hope Picasso treated his dog better than he treated people, because by and large he didn't treat people very well at all.
Lump is one of the "famous wiener dogs" listed in this article at Mental Floss Blog. Others are Andy Warhol's Amos and Archie, and David Hockney's Stanley and Boodgie. A most decent article indeed.