Citadel Nurgles Rot is a horrible, disgusting blob of pus, which is really great for getting a slime effect on your thumbnails.
Always shake the paint well before use. It actually starts out quite transparent and as the color builds up it changes to a really strong shade of green. It is best to apply it in thin layers rather than in one thick layer. Once it has dried it will take on a true high gloss finish.
Perfect for any poison or slime, so if you're painting it on one of your thumbnails, remember it's best to use it to finish the model as the last step when painting it in the nooks and crannies.