From the Super Mario Wiki
The Bob-omb Buddies (sometimes called Red Bob-ombs) are recurring allies to Mario of the Bob-omb species, introduced in Super Mario 64. They can be differentiated from the foes by their distinct pink or red color, their silver-colored caps on their tops, instead of the usual fuse, and a silver turn knob, signifying their pacifist and peaceful nature.
Super Mario series
Super Mario 64
In their first appearance in Super Mario 64, the Bob-omb Buddies help Mario by opening Cannons for him, and are shown to have a longstanding rivalry with the evil Bob-ombs, as this was the first time both groups were at war.
Super Mario 64 DS
Bob-omb Buddies reappear in Super Mario 64 DS, serving the same role that they had in the original game. However, additional Bob-omb Buddies have been placed in the courses that can either help Mario and his allies by giving the locations of the eight Red Coins in whatever level they're in, or detect the three caps that the player can use to transform into other players. Bob-omb Buddies have updated designs in this game. They wear shoes, unlike the Bob-omb Buddies in Super Mario 64 and Super Mario Galaxy 2. They also have little fuses that are hard to see on their cap.
They also appear in several minigames in this game.
New Super Mario Bros.
In New Super Mario Bros., Bob-omb Buddies appear in a number of minigames, including Sort or 'Splode, and Danger, Bob-omb! Danger!, that were carried over from Super Mario 64 DS. They are also known in this game as Red Bob-ombs.
Super Mario Galaxy 2
Bob-omb Buddies reappear in Super Mario Galaxy 2. Their only appearance in a galaxy is in the Throwback Galaxy where they give Mario information. In the first mission, Return of The Whomp King, they ask Mario to defeat the Whomp King for them. Later on in the second and third missions, Silver Stars in the Whomp Fortress and Whomp Silver Star Speed Run respectively, one Bob-omb Buddy hides five Silver Stars around the fortress and Mario has to go find them. One of the Bob-omb Buddies mentions that Mario looks familiar, referencing Super Mario 64 and its remake. This happens even with Luigi.
One Bob-omb Buddy makes an additional appearance on the Starship Mario, standing on a stump after Mario completes the first mission in the Throwback Galaxy. He asks if Mario has ever been to a Secret World, which is later revealed to be World S.
Several Bob-omb Buddies can be found along the ends of certain courts in the Nintendo 64 version of Mario Tennis, along with the standard Bob-ombs, and will explode if a tennis ball goes through them.
Mario Party series
Bob-omb Buddies (known in-game as Red Bob-ombs) appear in the Wario's Battle Canyon board in Mario Party. Like Black Bob-ombs, they blast the player off in a cannon. If the player lands on a Happening Space, they will move the cannons to a different direction. In this game, they are colored red instead of pink.
Mario Party 2
Bob-omb Buddies (known simply as Aliens) appear in Mystery Land in Mario Party 2. In this game, they are extraterrestrials. They warp the player to another location. They are also seen in the end, where one is turned back from a statue to an alien by the Superstar.
Mario Party 3
Mario Party Advance
Mario vs. Donkey Kong
Unspecified magenta-colored Bob-ombs appear in Mario vs. Donkey Kong, but only during the Donkey Kong battles in Mystic Forest, Twilight City, and their respective Plus World variants. They are thrown by Donkey Kong as his means of attack and must be used against him. Like with the regular Bob-ombs, the magenta Bob-ombs start flashing when they see Mario and will explode shortly after. Unlike regular Bob-ombs, the magenta Bob-ombs will not stop moving even when they are about to explode. In the Level 5-DK+ battle, the magenta Bob-ombs can destroy the blocks on the ground, opening up a Spike Trap.
Names in other languages