|This article is about the current version of DF.|
Enemies in sieges will often arrive riding on other creatures, their mounts. These mounts can not only add to the attacks of those mounted on them, but may also give their riders more abilities: their mounts might be able to fly or swim, might be building destroyers, might prevent the operation of bridges, might be faster and fleeter of foot, or they might just be plain scary in combat.
Enemy squads can appear with a single mount for the squad captain or individual mounts for each member of the squad (potentially including more than one species of mount). Some mounts such as giant bats or giant cave swallows possess the ability to fly, pathing over whatever walls and traps you have set up for them. This can lead to a great deal of fun if you do not have sufficient marksdwarves to deal with them. Some siegers also come on amphibious mounts, such as cave crocodiles and giant toads. Humorously, these units will disregard their rider's inability to breathe underwater or swim, and reports of amphibious mounts pathing into moats or rivers, only to have their goblin riders drown, are fairly common.Bug:926
There are three types of mounts: ordinary mounts ridden by Humans; above-ground (or "good") exotic mounts ridden by Elves; and underground (or "evil") exotic mounts ridden by Goblins. There are many creatures that have [MOUNT] or [MOUNT_EXOTIC] in their raw files, but below are some of the most common when an army besieges your fortress.
 Who rides what
- Goblin sieges have been known to ride elk birds, giant cave swallows, giant olms, giant bats, cave crocodiles, rutherers, jabberers, blind cave bears, and voracious cave crawlers. These are usually the only sieges where you need to worry about enemies flying into your fortress from above.
- Elves prefer arriving on foot, but when they do ride mounts, they usually use the dreaded unicorn, as well as various big cats. It is theoretically possible for them to arrive riding any exotic land animal, such as elephants, tigers, unicorns, or even giant mantises. Because of this, be prepared for an occasional flying mount when elves besiege your fortress.
- Human sieges will come riding camels (of both varieties), horses, and grizzly bears, in addition to bringing along squads of trained war animals, like giant cheetahs.
- Dwarves may field cavalry similar to human and goblin forces (should they have the luck to domesticate something,) but only in modded games wherein the player's civ is not the dwarves.
Beyond acting like a force multiplier, dead mounts can be butchered after the battle to feed your meat industry. A squad of cave dragons that is killed and hauled back inside your fort will produce a lot of meat products, making mounted sieges convenient food resupplies, if you are prepared to handle them that is. Note that goblins only have a single animal trainer, their general; if he falls (or, because of a bug, leaves the map), you will never see mounted goblin units again.
Note, that in the vanilla game, playable civs cannot, under any circumstances, field cavalry in fortress mode in the current version; this is regardless of race, not just dwarves.