Monsters are dangerous creatures of various sorts. While never rare in the less-civilized and wilder regions of Equestria and Equus as a whole, the proportion of regions of the world fitting the description "less-civilized and wilder" increased greatly after the Catastrophe and has declined only very slowly.
Travelers are advised to use caution and seek local knowledge about areas of frequent monster activity before setting out on any overland journey, especially outside of the most well-established routes. Common monsters in the Dusts include Soldier Rats, Dust Devils, the Ambusher Squirrel, Fire Ants and several species of Trolls. Scholars are divided about the classification of the Wirewind as a monster or a meteorological phenomenon.
Aspiring wizards sometimes attempt to make their mark on the craft by the creation of new varieties of monsters. This sort of activity, generally suppressed during the Golden Age, came back into vogue during the Dark Age. Hazards of this nature are too diverse to even survey here. One unfortunate category of such beings is undead.