From the Super Mario Wiki
Alarm Bob-ombs are a species of Bob-omb that appear in Mario & Luigi: Bowser's Inside Story and its remake, Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey. The Bob-ombs resemble small black-and-gold alarm clocks with wind-up keys and feet; their faces have round button-noses and clock hands that are angled to resemble angry eyes. The remake's shading also shows they have flat faces. Prima Games' strategy guide for Bowser's Inside Story erroneously refers to the bell on Alarm Bob-omb's head as a spike, and that Mario and Luigi cannot jump on it, even though they are safe to jump on in battle.
Their only form of attack is to dash back and forth across the screen in front of Bowser, hopping in place often and making an irritating beeping noise. Bowser must punch them when they line up with him to damage them and stop the attack; the explosion can damage and dizzy him. If not stopped soon enough, it begins to flash red and ring louder, alerting any Naplock that is present and sleeping; if there is one, it will reach out to hit the Alarm Bob-omb on its head, canceling the attack themselves. Alarm Bob-ombs explode upon defeat or successfully running into Bowser, and the explosion will wake up all sleeping Naplocks in the battle; this gives them the POW-Up status in the original game, or the Dizzy status in the remake.
Bowser can inhale Alarm Bob-ombs via Vacuum Block. Inside Bowser's body, they use the same attack on the Mario Bros., who must counter with their hammers. Since no Naplocks are able to turn it off here, they must land the counterattack quickly before it turns red and runs into them; the explosion will do significant damage and dizzy Mario or Luigi.
Alarm Bob-ombs return in Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey, where they additionally appear as enemies in the Bowser Jr.'s Journey mode. They only appear in the level Explosive Troops for one battle. Alarm Bob-ombs are melee troopers and are weak against Broozers.
Profiles and statistics
Mario & Luigi: Bowser's Inside Story / Mario & Luigi: Bowser's Inside Story + Bowser Jr.'s Journey
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