Doombats are one type of flying unit included in Prince Ansom's coalition against Stanley. Individually, Doombats are relatively weak in combatErf-b1-p113; however, they are very useful for scouting. It appears to cause Vinny distress (mental and/or emotional) to "watch" while one of the bats is croaked in combat.Erf-b1-p056 The Royal Crown Coalition uses the Doombats provided by Count Vinny Doombats as short recon throughout the story, but only so long as Vinny is present with the RCC.
A scouting bat discovered the incoming raids against Ansom's siege units, and additional bats mapped out a ring of dwagons that had apparently been deployed as a defensive formation for the wounded raiders. In each case, the bat was lost after encountering the enemy, being no match for a single dwagon, much less a stack.
After a force of forest units led by Ansom broke into the dwagon ring, a bat was sent into the protected center hex of the ring, and found it to be empty. Ansom did not consider this finding to be final, and went to see for himself. Wanda Firebaugh speculated that he believed that the center hex contained veiled units. These events indicate one limitation on doombats' scouting ability (they are apparently more susceptible to deception by veiling than a high-level warlord such as Ansom).
Transylvitian flying warlords can carry doombats in their capes and may thus serve as a sort of "carrier," effectively extending the operational range of doombats. (See Summer Update 010)