Not sure if it's been talked about already but i wanted to suggest:
Unranked ->
Ranked
Ludicolo boasts a unique typing that makes it a great abuser of rain. Especially in this current meta filled with fast but frail threats, its solid power, amazing speed under rain and great movepool allow it to demolish offense given the right amount of support.
Under rain a jolly Ludicolo packs
524 speed, enough to outspeed every scarfer up to base 110s (not included), but most importantly it outspeeds ash-greninja, every tapu (bar scarf koko) and very notably pheromosa. Outside of rain it still has enough speed to nail most landos and get a hit off on non-jolly/timid hoopa-u.
Base 90 SpA is definitely not overwhelming but under rain its surf is almost as strong as
tapu-koko's thunderbolt, and we all know how devastating that is. Other than that, it relies on coverage and some prediction to score supereffective hits that easily 2hko most of the meta.
Its 80/70/100 natural bulk is also very solid for an offensive mon, and can be compared to Volcarona's for an idea. It can usually take one neutral hit from a defensive mon and proceed to 2hko. Also the water-grass typing is great not only offensively but defensively too. Ludicolo easily tanks most priority moves (aqua jet, bullet punch), as well as having the ability to come in on EQs taking minimal damage.
However the thing that sets it apart from all other rain abusers is having a way to
hit fat waters incredibly hard. It can force in and KO tapu-fini with its grass STAB, and that's something that the likes of Kingdra wish they could do.
Here's a set I've been using recently on the ladder with great success:
Ludicolo @ Life Orb
Ability: Swift Swim
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Giga Drain
- Surf
- Ice Beam
- Focus Blast/Hp electric
Here are some calcs to put into numbers what i just said above (all assuming no stealth rocks)
252 SpA Life Orb Ludicolo Giga Drain vs. 252 HP / 100 SpD Tapu Fini: 182-218 (52.9 - 63.3%) -- 99.6% chance to 2HKO after Leftovers recovery
0 SpA Tapu Fini Moonblast vs. 0 HP / 4 SpD Ludicolo: 99-117 (32.8 - 38.8%) -- 99.3% chance to 3HKO
252 SpA Life Orb Ludicolo Surf vs. 0 HP / 0 SpD Tapu Koko in Rain: 285-335 (101.4 - 119.2%) -- guaranteed OHKO
252 SpA Life Orb Ludicolo Ice Beam vs. 252 HP / 0 SpD Tapu Bulu: 208-247 (60.4 - 71.8%) -- guaranteed 2HKO
252 SpA Life Orb Ludicolo Surf vs. 0 HP / 0 SpD Tapu Lele in Rain: 199-235 (70.8 - 83.6%) -- guaranteed 2HKO
252 SpA Life Orb Ludicolo Giga Drain vs. 0 HP / 0 SpD Greninja-Ash: 330-390 (115.7 - 136.8%) -- guaranteed OHKO
252 SpA Life Orb Ludicolo Surf vs. 0 HP / 0 SpD Pheromosa in Rain: 477-563 (168.5 - 198.9%) -- guaranteed OHKO
252 SpA Life Orb Ludicolo Surf vs. 0 HP / 0 SpD Charizard-Mega-X in Rain: 257-304 (86.5 - 102.3%) -- 12.5% chance to OHKO
252 SpA Life Orb Ludicolo Surf vs. 0 HP / 0 SpD Metagross-Mega in Rain: 208-246 (69.1 - 81.7%) -- guaranteed 2HKO
I'm obviously not trying to paint Ludicolo as the overlord of OU, but I believe it should be at least ranked. It definitely has a niche and with the correct support it can do very good work as a late game cleaner or as a mid-game breaker.
Some replays as well:
http://replay.pokemonshowdown.com/gen7oususpecttest-533460836 Could have done much more if not for scarf koko
http://replay.pokemonshowdown.com/gen7oususpecttest-533493266 Mono dark (?) but still had a few checks and it did work nonetheless
http://replay.pokemonshowdown.com/gen7oususpecttest-533501844 AV tangrowth and tapu fini were not enough
P.S: I just posted a RMT on the team I used on the replays, check it out for more about how I feel Ludicolo should be used in OU and the team support options to make it work.
http://www.smogon.com/forums/threads/mexican-rain-ft-mega-pinsir.3595919/