Most Disappointing Mega Evolution

[Six Trails]

Besides Mega Latios (since he is objectively the answer to this thread), which Mega Evolution is the most underwhelming/disappointing to you? For me it's Mega Heracross because it got an amazing Attack stat and good ability only to get it's Speed nerfed and put at an incredibly low Speed tier for OU. Mega Garchomp is pretty bad too, but it has better potential to go mixed than regular Garchomp so it's a little more forgivable for me.

 

[Uchiha]

Mega Heracross is decent on the right team, I've seen top rankers using it.

Garchomp
The fairy pig

 

[Six Trails]

Audino? If so, I agree with that one too. It would be a lot better if it just kept Regenerator instead of getting a pointless ability for Singles.