From the Super Mario Wiki
“Ready for blast-off! Come on, hop in the cannon!”
The Bob-omb Buddies (sometimes called Red Bob-ombs) are recurring allies to Mario of the Bob-omb species. They can be differentiated from the foes by their distinct pink or red color and their silver-colored caps on their tops, instead of the usual fuse.
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 (but are peace loving Bob-ombs), and are shown to have a longstanding rivalry with the evil Bob-ombs, as this was the first time both groups were at war. The Bob-omb Buddies in the "Super Mario 64" game version are colored pink, not to be confused with earlier pinkish-red versions.
Super Mario 64 DS
They also help Mario and his allies in Super Mario 64 DS by giving the locations of the eight Red Coins in whatever level they're in as well as opening cannons as usual. Also, Bob-omb Buddies in this game 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. In one mini-game, Sort or 'Splode, the player separates Bob-omb Buddies and Bob-ombs by moving the Bob-omb Buddies on the left side while moving Bob-ombs on the right. Eventually, the hatch on the bottom of the screen opens and more Bob-omb Bubbies and Bob-ombs enter. If the player places the Bob-ombs incorrectly, the Bob-ombs in that section explodes. If the player takes too long, the Bob-ombs on their appropriate sections remain and are counted to the total. When there are enough Bob-ombs in one section, these Bob-ombs are stored and counted toward the total. In the minigame, the Bob-ombs have visible fuses that are lit, which are extinguished when they are sorted into their corresponding boxes.
New Super Mario Bros.
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 help Mario along his missions. In the first mission, Return of the Whomp King, they ask Mario to defeat the Whomp King for them. They will thank Mario for doing this. 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.
A Bob-omb Buddy appears in the Game Boy Color version of Mario Tennis. It can be seen inside the castle in Mario World during the story mode of the Mario Tour.
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
Names in Other Languages