Bob-omb (Paper Mario: The Origami King)

Bob-omb, or Bobby as referred to by Olivia, is an ally to Mario in Paper Mario: The Origami King. He is an amnesiac Bob-omb who joins Mario and Olivia's quest while attempting to recall his memories.

In battle, after Mario has attacked, Bob-omb uses Bomb Bump, ramming into the nearest enemy, dealing 20 damage, in a similar fashion to Bombette in Paper Mario, although he sometimes trips and deals no damage. Unlike most other Bob-ombs, Bob-omb does not have a fuse.

Background
Sometime prior to the events of Paper Mario: The Origami King, Bob-omb had lost a friend, also named Bob-omb. After the events, Bob-omb kept his fuse as a memory.

Presumably later, Bob-omb was booked with a group of Bob-omb friends on a cruise in the VIP stateroom on The Princess Peach. However, during the trip, Gooper Blooper attacked the ship. The group attempted to defend the ship to no avail, and during the battle, Bob-omb was knocked off the boat, and his fuse was knocked loose and lost.

Sometime later, Bob-omb washed ashore at Toad Town, with amnesia. After regaining consciousness, Bob-omb set off alone on the route towards Overlook Mountain, looking to recover his memories.

Paper Mario: The Origami King
By the time Mario and Olivia defeat Colored Pencils and unravel the red streamer used in King Olly's plot to take over the world, Bobby has boarded a cable car headed towards Autumn Mountain. Mario and Olivia end up boarding that same car.

During the trip, Bob-omb introduces himself, stating he only remembers his name, Bob-omb, and reveals he has amnesia, albeit not knowing the correct term for the condition, and states his purpose for going on the journey. Olivia then brings up the idea of Bob-omb joining them as a chance to help him recover his memories. Initially, Bob-omb is skeptical, stating he thought he would be a burden to the two, after which Olivia abandons the idea. Bob-omb, however, thinks about the opportunity, and brings it up again shortly afterward.

By the time the cable car reaches Autumn Mountain, Mario has agreed to take Bob-omb under their wing. After getting off, Olivia refers to him as Bombert, but Bob-omb corrects her, leading her to begin thinking of a new nickname (settling on "Bobby"). Shortly, Bob-omb runs off to investigate a small valley in the mountain, which is in fact a dried up river, forcing Mario and Olivia to catch up with him. On the way out of the river, Bob-omb tries to make friend with a Spiny turned Folded Soldier, to which Olivia stops him. After the Spiny, the trio enters a dried up lake, with a Water Vellumental Magic Circle nearby

As the trio explores the mountain, Bob-omb runs off at twice, the first time to take in the sight of the Water Vellumental Shrine, and the second during a walk in the Tall Grass Plains, in which he meets and befriends a Sombrero Guy.

Then, while crossing a bridge to the temple, a Paper Macho Goomba appears, whom Bob-omb also attempts to befriend. The Goomba then knocks Bob-omb off the bridge, and Mario jumps off in pursuit, landing in the Autumn Valley.

Mario ends up continuously having to rescue Bob-omb making it back to the shrine. Once they do make it back, Bob-omb and Mario stand on dual pressure plates, opening the shrine. Bob-omb, however, decides to remain near the entrance in fear.

After Mario defeats the Water Vellumental and Olivia learns how to become it, she fills up the lake, to Bob-omb's amazement, only to realize they can't paddle down it. To proceed, the trio returns to the Sombrero Guy and gets some canned food to lure down a monkey, who is actually a Toad oarsman, who then takes them down the lake.

Somewhere down the lake is Shogun Studios. Bob-omb tags along, aside from the House of Tricky Ninjas, and joins the audience for a performance directed by Rubber Band.

After Mario defeats Rubber Band and unravels the blue streamer, the staff of Shogun Studios throw celebratory fireworks. Looking at the fireworks causes Bob-omb to regain his memories.

The trio continues the boat tour to Sweetpaper Valley following the yellow streamer, but following an encounter with King Olly, a boulder appears, crushing Olivia. Seeing this, Bob-omb takes charge, and he and Mario head back to Toad Town and take a boat across the Great Sea to the Princess Peach, now overtaken with black ink. Inside the VIP stateroom is a lockbox containing the item Bob-omb is looking for, which is promptly taken by Gooper Blooper.

After Mario recovers the box, the two head back to Sweetpaper Valley. Bob-omb comes to terms to tell Mario his backstory, and reveals the item inside the lockbox, his late friend's fuse. He puts it on, and thanks Mario and Olivia as his last words. Mario attempts to stop him, but Bob-omb explodes, sacrificing his life to destroy the boulder trapping Olivia.

Upon learning of Bob-omb's demise, Olivia runs off crying, and sits on a bench in Breezy Tunnel trying to cope, to no avail. Mario goes into the tunnel a short distance before running into Bob-omb's spirit, who has him cheer up Olivia, lest his sacrifice be in vain. Mario must then use his Goomba Mask to give Olivia the motivation to continue.

Trivia

 * Bob-omb refers to his amnesia as "Thinky Thinky Panic", which itself is a pun on Yume Kōjō: Doki Doki Panic, where Bob-ombs debuted.
 * In the Japanese version, Bob-omb calls Mario "aniki", or "big brother" (which can figuratively be used as an honorific for a superior), implying that the former is younger than him.