I have been using this team for over six months now, recently I've been using it on shoddy battle and have found it fairly effective there (though it's really only a 55%/45% win/loss ratio with it) and I want to improve it:
MONOTYPE POISON
Mission: My mission with this team is to not only have fun, but to whoop ass while I'm doing it. I'm trying to be faithful to the old days of R/B/Y and so in honor of Koga I have a Muk and Venomoth. This team has some synergy and they work well together, but it needs improvement. I don't think I can improve it any more on my own though. I've exhausted my own ideas.
At worst, I'd like to do better than Koga haha.
Crobat
252 Speed / 252 SpAttack
Timid (+Speed -Attack)
Inner Focus (Prevents Flinching)
Focus Sash
Taunt
Heat Wave
Air Slash
Hypnosis
Crobat is godsend lead. He will stop trick room, rain dance – and with proper reading I can also stop a swords dance or baton pass or destiny bond. However, his main job is to scout or force or an enable a switch.
He used to be a physical attacker but recently I found Heat Wave was too good to pass up. It just surprises so many people. Besides, I've found Air Slash is a superior attack option for a hypnosis + flinch combo.
Hypnosis is what I do as a last resort – when I just can't read my opponent. If I'm not sure wether Swampert will Stealth Rock or Stone Edge, I'll risk a hypnosis. Otherwise, I'll taunt or attack. Usually after sleeping, I switch in Toxicroak or Muk, who are specialized in handling a wide variety of foes.
Against a faster pokemon like Aerodactyl or Electrode, I will switch in Toxicroak or Muk.
Gengar
252 Speed / 252 SpAttack
(Adamant +SpAttack -Attack)
Levitate
Focus Sash
Shadow Ball
Thunderbolt
Focus Blast
Destiny Bond
Gengar sweeps. Scizor and priority attackers are his biggest fear, but with good prediction, Destiny Bond forces a switch or allows me to hit them at least once or it kills them, which is lovely.
I tend to send out Gengar mid-fight so that I can switch him in on an earthquake or a fake-out.
Venomoth
252 Speed / 252 SpAttack
(Timid +Speed -Attack)
Tinted Lens
Choice Specs
Bug Buzz
Energy Ball
Sleep Powder
Psychic
Venomoth is my choice attacker. He annihilates anyone who underestimates him. That said, he is easily countered by a speedy foe or someone like Charizard. If he's faster though, Venomoth will tend to OHKO or 2HKO his opponents. Energy Ball and Psychic are saved for 4x weaknesses and Sleep Powder is when I misread my opponent, otherwise I'll Bug Buzz away until death. Venomoth carries his weight, at any rate.
Toxicroak
252 Attack / 128 Hp / 128 Defense
Dry Skin
Adamant (+Attack -SpAttack)
Focus Sash
Ice Punch
Bullet Punch
Cross Chop
Sucker Punch
Priority attacker. He hits pretty hard and covers a lot of pokemon, plus he has great staying power and loves to switch in on surf. I will often switch him in on Aerodactyl, Ice Punch and Bullet Punch assure a KO on many pokemon, Cross Chop devastates walls like Blissey or Snorlax.
Arbok
252 Attack / 252 Speed
Adamant (+Attack -SpAttack)
Intimidate
Choice Scarf
Earthquake
Water Tail
Seed Bomb
Gunk Shot
Initially, Arbok started out as a full-on attacker with a choice band, but I found that Heatran was totally wrecking this team (he was not only speedy, but had a powerful earth move and was immune to Muk's Fire Blast and Crobat's Heat Wave and had a 4x resistance to Bug Buzz – there was nothing I could do to stop this guy until I got a choice scarf). Although he lacks power, Arbok is speedy enough to get some crucial hits in.
Muk
128 hp / 128 Def / 252 SpD
Modest (+SpAttack -Attack)
Sticky Hold
Black Sludge
Acid Armor
Rest
Thunderbolt
Fireblast
Muk is fairly sturdy against special attackers but is generally ill-suited to fight them, he actually takes on the role as a physical wall with Acid Armor and Rest. Although he might be better suited with toxic, I've found the extra user of an electric or fire move is beyond necessary. Muk is my anti-Siczor anti-Gyrados basically. Although he won't OHKO the latter with thunderbolt, he may get the kill if the user just can't afford to switch in someone else.
I'm not really sure about Muk though. He's very situational, but of the 4 other pokemon that once occupied this place on the team (SpAttacker-based Roserade, SpD wall Tentacruel, Pain Split Wall Weezing, Utility Qwillfish) Muk has performed the best of all.
Overall Commentary:
A few people who have battled me question my use of all poison, asking "What do you do about Earthquake?" Earthquake is rarely an issue, as pokemon who hit hard with earthquake are generally devastated by someone like Arbok (who has EQ, Seed Bomb and Aqua tail). Venomoth does not take extra damage from earthquake and Crobat and Gengar avoid it completely. Muk can acid armor and rest through an earthquake, rendering the damage minor.
A speedy psychic type may be the end of this team, however priority moves from Toxicroak (specifically sucker punch), Sleep Powder/Hypnosis, Gengar's speed + Shadow Ball, and Venomoth's bug buzz are generally more than enough to deal with a psychic foe. So far I've yet to run into a pokemon which can solo sweep this team (which would be pretty embarassing). Even against Ubers, this team is capable of holding its own.
But I am hesitant to say that it's complete. I'd really like some C&C here. Since this is my first RMT, I hope I've done this correctly, but don't spare the rod, if you think I've done something noobish here, call it out. I'd love some suggestions on alternate poison pokemon though, Beedrill/Qwillfish/Tentacruel/Roserrade/Ariados/Venasaur/etc are pretty cool but don't really fit this team, or atleast I can't seem to make them fit.
MONOTYPE POISON

Mission: My mission with this team is to not only have fun, but to whoop ass while I'm doing it. I'm trying to be faithful to the old days of R/B/Y and so in honor of Koga I have a Muk and Venomoth. This team has some synergy and they work well together, but it needs improvement. I don't think I can improve it any more on my own though. I've exhausted my own ideas.
At worst, I'd like to do better than Koga haha.
Crobat

252 Speed / 252 SpAttack
Timid (+Speed -Attack)
Inner Focus (Prevents Flinching)
Focus Sash
Taunt
Heat Wave
Air Slash
Hypnosis
Crobat is godsend lead. He will stop trick room, rain dance – and with proper reading I can also stop a swords dance or baton pass or destiny bond. However, his main job is to scout or force or an enable a switch.
He used to be a physical attacker but recently I found Heat Wave was too good to pass up. It just surprises so many people. Besides, I've found Air Slash is a superior attack option for a hypnosis + flinch combo.
Hypnosis is what I do as a last resort – when I just can't read my opponent. If I'm not sure wether Swampert will Stealth Rock or Stone Edge, I'll risk a hypnosis. Otherwise, I'll taunt or attack. Usually after sleeping, I switch in Toxicroak or Muk, who are specialized in handling a wide variety of foes.
Against a faster pokemon like Aerodactyl or Electrode, I will switch in Toxicroak or Muk.
Gengar

252 Speed / 252 SpAttack
(Adamant +SpAttack -Attack)
Levitate
Focus Sash
Shadow Ball
Thunderbolt
Focus Blast
Destiny Bond
Gengar sweeps. Scizor and priority attackers are his biggest fear, but with good prediction, Destiny Bond forces a switch or allows me to hit them at least once or it kills them, which is lovely.
I tend to send out Gengar mid-fight so that I can switch him in on an earthquake or a fake-out.
Venomoth

252 Speed / 252 SpAttack
(Timid +Speed -Attack)
Tinted Lens
Choice Specs
Bug Buzz
Energy Ball
Sleep Powder
Psychic
Venomoth is my choice attacker. He annihilates anyone who underestimates him. That said, he is easily countered by a speedy foe or someone like Charizard. If he's faster though, Venomoth will tend to OHKO or 2HKO his opponents. Energy Ball and Psychic are saved for 4x weaknesses and Sleep Powder is when I misread my opponent, otherwise I'll Bug Buzz away until death. Venomoth carries his weight, at any rate.
Toxicroak

252 Attack / 128 Hp / 128 Defense
Dry Skin
Adamant (+Attack -SpAttack)
Focus Sash
Ice Punch
Bullet Punch
Cross Chop
Sucker Punch
Priority attacker. He hits pretty hard and covers a lot of pokemon, plus he has great staying power and loves to switch in on surf. I will often switch him in on Aerodactyl, Ice Punch and Bullet Punch assure a KO on many pokemon, Cross Chop devastates walls like Blissey or Snorlax.
Arbok

252 Attack / 252 Speed
Adamant (+Attack -SpAttack)
Intimidate
Choice Scarf
Earthquake
Water Tail
Seed Bomb
Gunk Shot
Initially, Arbok started out as a full-on attacker with a choice band, but I found that Heatran was totally wrecking this team (he was not only speedy, but had a powerful earth move and was immune to Muk's Fire Blast and Crobat's Heat Wave and had a 4x resistance to Bug Buzz – there was nothing I could do to stop this guy until I got a choice scarf). Although he lacks power, Arbok is speedy enough to get some crucial hits in.
Muk

128 hp / 128 Def / 252 SpD
Modest (+SpAttack -Attack)
Sticky Hold
Black Sludge
Acid Armor
Rest
Thunderbolt
Fireblast
Muk is fairly sturdy against special attackers but is generally ill-suited to fight them, he actually takes on the role as a physical wall with Acid Armor and Rest. Although he might be better suited with toxic, I've found the extra user of an electric or fire move is beyond necessary. Muk is my anti-Siczor anti-Gyrados basically. Although he won't OHKO the latter with thunderbolt, he may get the kill if the user just can't afford to switch in someone else.
I'm not really sure about Muk though. He's very situational, but of the 4 other pokemon that once occupied this place on the team (SpAttacker-based Roserade, SpD wall Tentacruel, Pain Split Wall Weezing, Utility Qwillfish) Muk has performed the best of all.
Overall Commentary:
A few people who have battled me question my use of all poison, asking "What do you do about Earthquake?" Earthquake is rarely an issue, as pokemon who hit hard with earthquake are generally devastated by someone like Arbok (who has EQ, Seed Bomb and Aqua tail). Venomoth does not take extra damage from earthquake and Crobat and Gengar avoid it completely. Muk can acid armor and rest through an earthquake, rendering the damage minor.
A speedy psychic type may be the end of this team, however priority moves from Toxicroak (specifically sucker punch), Sleep Powder/Hypnosis, Gengar's speed + Shadow Ball, and Venomoth's bug buzz are generally more than enough to deal with a psychic foe. So far I've yet to run into a pokemon which can solo sweep this team (which would be pretty embarassing). Even against Ubers, this team is capable of holding its own.
But I am hesitant to say that it's complete. I'd really like some C&C here. Since this is my first RMT, I hope I've done this correctly, but don't spare the rod, if you think I've done something noobish here, call it out. I'd love some suggestions on alternate poison pokemon though, Beedrill/Qwillfish/Tentacruel/Roserrade/Ariados/Venasaur/etc are pretty cool but don't really fit this team, or atleast I can't seem to make them fit.