A watchdog is an enemy found in Metal Slug: 1st Mission.
Information
Watchdogs are Rebel Army dogs who patrol the Prison Camps. It'll bark out any suspecting escapee it sees which causes an off-screen Rebel guard to aim a patrol light around the area for a few seconds. Should the Hero be caught in the light, a timed reticle then homes on the Hero and fires.
Watchdogs cannot be killed or subdued by the Hero.