The Galley-Wag (alternatively Golliwog, though his birth name is a 'finely-modulated subsonic tone') is a creature from a different dimension called the Black Matter Cosmos. He is described as being made of dark matter.
He, along with many of his kind, was used as a slave on board a galley by a group of pink humanoids, until he escaped to earth, where he ended up in Toyland. There he met Frankenstein's Monster, who provided him with two companions: the Dutch Dolls.
Galley-Wag is the owner of a ship called the Rose of Nowhere , a balloon-type craft that uses pataphysical rose-propulsion which allows it to cross dimensions and the void of space. He is also an acquaintance of Prospero.
He plays a secondary role in the climax of The League of Extraordinary Gentlemen: Black Dossier, in which he rescues Mina and Allan and takes them to the Blazing World. He also plays a part in Minions of the Moon, in which he, his dolls and Mina were sent on a mission to the Moon by Prospero to avoid a war between the Selenites and the Lunites.
The Galley-Wag is capable of emitting a loud screaming noise that can apparently shake the earth and knock down anyone who hears it. He uses this to hold off Jimmy Bond, Emma Night and Hugo Drummond in The Black Dossier. His text balloons in the comic are colored black, possibly to indicate he has either a deep or shrill alien voice.
Galley-Wag is based on the mischievous but gentle Golliwogg from the children's book The Adventures of Two Dutch Dolls and Golliwogg written by Florence Kate Upton in 1895, depicted as a type of rag doll. While the Golliwogg was once a popular traditional toy and beloved character, in contemporary times the image of the doll has become the subject of heated debate since it could be considered a dated racial stereotype of people of African descent, and thus distribution of the image is rare. Alan Moore and Kevin O'Neill reimagined the Golliwogg as an extradimensional being made of dark matter, and reprises the character's kindly nature.
The pink-skinned slavekeepers who had captured Golliwog are based on the alien conqueror Kanjar Ro, enemy of DC Comics' Justice League of America.