Goblins are a small humanoid species on The Disc. They were generally despised by most other species until the events of Snuff, where they made their debut appearance and their culture was fleshed out.
Ponder Stibbons once played the role of Third Goblin in a school play.
Culture & Religion
Historically, goblins have been treated as vermin, not humanoids, with no rights under the law. They could be enslaved or exterminated, with no consequences.
Goblins, like some Dwarfs, typically live underground in large cave systems. Some live in the caverns on the Ramkin country estate, Crundells. Goblins have good night vision, living underground. Their language is very difficult for non-goblins to understand, and when they speak the common tongue, it sounds mechanical, like they are opening and closing a box for each syllable. They wear clothing, make jewelry, create tiny beautiful ceramic boxes, harvest wild plants, drink alcohol, and sometimes -- people say -- they steal chickens.
In Snuff, goblins and their culture/religion are explored in greater depth. Their religion, Unggue, is based around the belief that everything that was once part of your body is always part of your body, and thus, it must be buried with you after death.
Because of their non-humanoid status, finding decent employment was difficult, historically. In a discussion about Dwarfs keeping up old traditions, it is said that rich Dwarfs in non-Dwarfish professions, such as the clerical trade, will employ goblins to do nothing but hit small ceremonial anvils with small ceremonial hammers all day, purely to create the sort of atmosphere in which a Dwarf finds it easy to think.
Due to their former non-status, goblins were used as slave labour on plantations by unsavoury characters such as Gravid Rust.
Aptitudes & Recent Status
As a species, their unique talents and abilities finally came to the public eye in the events of Snuff. Thereafter, goblins gained humanoid status. They now find work where their natural understanding of machinery comes in handy, such as on the clacks system or Moist von Lipwig's new railway engines.
From Raising Steam: "Goblins, quite apart from now being ubiquitous in the clacks industry, were also doing very well and picking up serious folding money in the ceramics business. Goblin pots were beautiful, extremely fine and as iridescent as a butterfly’s wing."
Some goblins are incredibly talented musicians, with the young harpist and composer Tears of the Mushroom being a prominent example.
Apparently, goblins are natural-born tinkerers. One invented the bicycle in Raising Steam:
Vetinari finally did smile and said, “A remarkable velocipede, Mister Of the Wheel the Spoke. I do believe that Leonard of Quirm had a similar idea, but now we are in a world of motion, I see no problem here."
Relation to other species
Gnolls, in earlier books, are explicitly described as a sort of stone-goblin. (Use of the word "goblin" supports the position that originally, Terry Pratchett intended them to be the Discworld analogue of Tolkien's Orcs, as they are vicious, sadistic, murderous, and attracted to filth). However, by the time of Jingo, all that appears to survive of this original concept is the attraction to filth and possibly a little residual cruelty.
In Unseen Academicals, a new race, initially confused with goblins, is introduced to the Discworld. This association is refuted at the end of the book, where Lord Vetinari remarks that Orcs must have been bred from men - only humanity has the inherent cruelty requisite for being subverted into orcishness; goblins are too small-time. TP really doesn't have that much respect for humankind...
- Of the Lathe the Swarf
- Of The Wheel the Spoke
- Of the Wind Regretfully Blown ("Billy Slick")
- Shine of the Rainbow
- Sound of the Rain on Hard Ground
- Tears of the Mushroom
- The Cold Bone Wakes
- Of the Twilight the Darkness
- By adoption
On the change of the nature of Gnolls through the books: there is a famous critical comment on Terry Pratchett's work, comparing him to Tolkien, but with the caveat that "in these Détènte-driven days, Pratchett has no horrors waiting to emerge from the East". (He doesn't have an East as such, in fact).
It could just be that an Orc-analogue simply wasn't needed - look at the way Elves have filled the niche for a non-human Other, which is inimical to mankind - and having introduced Gnolls in an earlier book, they simply got recycled to fill a different socio-ecological niche more suited to Discworld. Which as an argument holds really well together until you get to Unseen Academicals and have to rip it all up and start again, when a new race, which might originally have begun as Goblins (or men - see the article) but was seriously improved on by Igors working for the Dark Side, is introduced.