OK, I've been waffling between two different Dark Horse teams, but here goes...
Pokemon Showdown! Username: Hogg Horse (I also am using this for UU's DH this month, but I have not yet played any OU games on this alt.)
Prior Hall of Fame Standing: N/A
Current Dark Horse Pokemon: Shedinja & Alomomola
Explanation of Dark Horse(s)
OK, Sheddy stall is something that I've been playing with a lot lately.
Meowiekins made a Shedinja stall team in UU that peaked #1, and messing around with it was the most fun I've had playing stall in ages. Shedinja is not really used as a sweeper so much as a defensive pivot and phazer (hell, its mere existence forces switches). I've been curious for a while if I could make Shedinja stall OU-viable. On the one hand, some really nasty threats like Ferrothorn, Garchomp, Bisharp and Tyranitar make it really dangerous to play with the lonely little bug. On the other hand, Mega-Sableye is just about the perfect partner for Shedinja, bouncing back status and entry hazards and being the best Ferrothorn counter in the game. Meanwhile, Shedinja can hard counter some super dangerous threats, including basically all Mega-Metagross, most Thundurus and Keldeo, and just about anything wearing a Choice item.
Alomomola is a stall staple for a reason. I needed a bulky pivot that could switch into Azumarill, and Momo is bulky enough to avoid the 2HKO from CB Play Rough, which is not something most pivots can say. While I still miss Amoongus, who I had planned on using as my second DH (looked at the 1695 stats instead of the 1825 stats by mistake :(), Momo gets Knock Off, which Amoongus would kill to have, and can also pass gargantuan Wishes.
I tested this concept on the suspect ladder (using test teams with Chesnaught and Amoongus, because I assumed ONE of them would end up as a Dark Horse this month... silly me), and got reqs with it, so I know that it works in OU despite having some issues. Now that the ladder is starting to settle down, it's time to see how the rest of this goes!