When a colleague you don't think too highly of gets promoted...

[TwoTierStollen]

The type that opens their mouth and lets their belly rumble

Happens all the time you just have to stay calm and rise above it .

Assuming they are genuinely bad at their job, vs not someone you rate personally, be a bit irritated and let off steam to someone trusted (crucially not a colleague) and then move on. Ultimately they're either going to come up stuck, end up showing themselves up for being shit or are the sort of person who talks the talks but the whole world knows they're a bit crap.

Yes, this is my letting off steam stage here.

are the sort of person who talks the talks but the whole world knows they're a bit crap.
Didn't think the boss would fall for it tbh. I think that's the biggest surprise.