Finally, one of my favorite Unova Pkmn. She's one of the reasons why I chose the Black version instead of White.
Bulky Buzzard
Ability: Overcoat
Nature: Careful/Impish
Item: Leftovers
Toxic
Roost
Brave Bird
Taunt/Whirlwind/Knock Off
Pretty much the only Mandibuzz you will ever see, but it's the best and it's good at what it does: wall. Toxic is really the best way to deal any real consistent damage with Mandi's mediocre offensive marks, while Roost lets you outstall the opposition. Brave Bird is Mandi's strongest STAB move; it stops you from becoming completely helpless against fast Taunters (like Crobat) and you can just Roost off the recoil damage. The last slot depends on your own taste—Taunt can shut down other walls, Whirlwind is good for stat-boosters and if you have entry hazards set up, Knock Off can screw over things that rely on items (Choice users and their Bands/Scarfs, walls and their Leftovers, NFEs and their Eviolites, etc.).
*Hippowdon would make a good partner for Mandibuzz. It's Ground-typing can stand up against Electric and Rock attacks, making it an effective shield against two of Mandi's weaknesses, it can instantly create a sandstorm (good with Overcoat) and can reliably set up Stealth Rock. Claydol is good too for similar reasons, and it can Spin away the opposition's Stealth Rock, which, as a wall, Mandi hates. Something that can take Ice-type attacks is recommended to add to you team because the vulture and the hippo are weak to Ice.
Ride the (Tail)Wind
Ability: Overcoat
Nature: Impish/Careful
Item: Leftovers
Tailwind
U-Turn
Roost
Brave Bird/Taunt
This makes Mandi more of a team player. Start with Tailwind and use U-Turn to both damage the opponent and switch to a slow but powerful counter, like Swampert, Ursaring, whatever you wish. Roost off any damage taken from Brave Bird if you think you can really nail something on your own. Taunt makes it even safer for sweepers to come in because it guarantees the opposition can't hit you with any Thunder Waves, Will-o-Wisps, etc.
Scheming Vulture
Ability: Overcoat
Nature: Timid
Item: Leftovers
Nasty Plot
Air Slash
Dark Pulse
Roost
Really more of a novelty set for Mandi's mediocre offensive power, and because Honchkrow hits way harder with it but the vulture still at least has the move pool (and she's must sturdier than the boss raven). Nasty Plot raises Mandi's Sp. Attack to, respectable, levels, Air Slash and Dark Pulse offer special STABS, and both are powerful with a chance to flinch the opponent. Roost off any damage taken and proceed to sweep. I suggest pairing this set with something that can break through Steel-types or those armored annoyances can stand in your way all day.