This is my second attempt at this, I added in more text so I was told there wasn't enough. I've only been on shoddy for a day or so and this is my first team. Having some success but I was wondering what changes could be made to make it better. I'm not that well versed in aspects of the metagame so, please go easy 
Lead:
Adamant Sandslash @ leftovers
Ability: Sand veil
EVs: 252 HP, 252 Atk, 4 Def
Earthquake
Nightslash
Stealth Rock
Rapid Spin
Basically a good attacking/ defensive poke. Nightslash is there to take care of those pesky pixies that I see quite often as leads. Earthquake gives good type coverage, STAB and deals with Arcanine and other fire type leads. Stealth Rock to set up early if I get a chance and rapid spin incase the opponent has the same idea.
Bulky Water:
Bold Slowbro @ Leftovers
Ability: Own Tempo
EVs: 252 HP, 4 Spe, 252 SpD
Psychic
Surf
Rain Dance
Slack Off
Obligatory bulky water. Psychic is there for STAB and to take fighting or flying types. Surf is STAB as well and is a generally good move. Slack Off for instant recovery and added bulkiness. Slowbro is bulky enough to take a turn to set up Rain Dance which has three purposes, giving a boost to Surf, benefiting my Ludicolo's Rain Dish ability and Surf, and serving as recovery for my Toxicroak with Dry Skin.
Offensive Sponge:
Calm Ludicolo @ Choice Specs
Ability: Rain Dish
EVs: 204 HP, 104 Spe, 76 SpA, 124 SpD
Grass Knot
Ice Beam
HP Electric
Surf
Ludicolo is excellent at dealing with fellow Water and Grass types, running Grass Knot which can 2HKO most Milotics and OHKO Quagsire. Ice Beam deals with Roserade and other Grasses. HP Electric is for flying types and Surf is the obligatory STAB.
Offensive Tank-
Lonely Hariyama @ Leftovers
Ability: Thick Fat
EVs: 80 HP, 172 Atk, 252 Def, 4 Spe
Ice Punch
Knock Off
Whirlwind
Revenge
Hariyama acts as an anti-sweeper tank, running Knock Off and Whirlwind to mess with Swords Dancers and those with CB or Life orbs etc. Revenge is for dealing with normal types such as Ursaring, Chansey, Miltank etc. Finally, Ice Punch deals with Dragons and Flying types.
Now the next two I doubt a bit because I don't exactly know what niche they occupy on my team. I mean Toxicroak is supposed to be a sweeper but in execution I find it dies horribly.
Jolly Drapion @ Scope Lens
Ability: Sniper
EVs: 252 Atk, 4 Def, 252 Spe
Cross Poison
Earthquake
Ice Fang
Night Slash
I think this is the one of the default movesets given at smogon, meant to exploit Sniper Ability. Cross Poison and Night Slash are STAB and both have high CH ratios. Ice fang deals with ground types and Earthquake is there for type coverage.
Adamant Toxicroak @ Life Orb
Ability: Dry Skin
EVs: 4 HP, 252 Atk, 252 Spe
Cross Chop
Sucker Punch
Swords Dance
Taunt
Taunt and Sucker Punch go together to ensure Sucker Punch's success. Swords Dance is pretty self explanitory and Cross Chop is a good STAB move.
Adamant Sandslash @ leftovers
Ability: Sand veil
EVs: 252 HP, 252 Atk, 4 Def
Earthquake
Nightslash
Stealth Rock
Rapid Spin
Basically a good attacking/ defensive poke. Nightslash is there to take care of those pesky pixies that I see quite often as leads. Earthquake gives good type coverage, STAB and deals with Arcanine and other fire type leads. Stealth Rock to set up early if I get a chance and rapid spin incase the opponent has the same idea.
Bulky Water:
Bold Slowbro @ Leftovers
Ability: Own Tempo
EVs: 252 HP, 4 Spe, 252 SpD
Psychic
Surf
Rain Dance
Slack Off
Obligatory bulky water. Psychic is there for STAB and to take fighting or flying types. Surf is STAB as well and is a generally good move. Slack Off for instant recovery and added bulkiness. Slowbro is bulky enough to take a turn to set up Rain Dance which has three purposes, giving a boost to Surf, benefiting my Ludicolo's Rain Dish ability and Surf, and serving as recovery for my Toxicroak with Dry Skin.
Offensive Sponge:
Calm Ludicolo @ Choice Specs
Ability: Rain Dish
EVs: 204 HP, 104 Spe, 76 SpA, 124 SpD
Grass Knot
Ice Beam
HP Electric
Surf
Ludicolo is excellent at dealing with fellow Water and Grass types, running Grass Knot which can 2HKO most Milotics and OHKO Quagsire. Ice Beam deals with Roserade and other Grasses. HP Electric is for flying types and Surf is the obligatory STAB.
Offensive Tank-
Lonely Hariyama @ Leftovers
Ability: Thick Fat
EVs: 80 HP, 172 Atk, 252 Def, 4 Spe
Ice Punch
Knock Off
Whirlwind
Revenge
Hariyama acts as an anti-sweeper tank, running Knock Off and Whirlwind to mess with Swords Dancers and those with CB or Life orbs etc. Revenge is for dealing with normal types such as Ursaring, Chansey, Miltank etc. Finally, Ice Punch deals with Dragons and Flying types.
Now the next two I doubt a bit because I don't exactly know what niche they occupy on my team. I mean Toxicroak is supposed to be a sweeper but in execution I find it dies horribly.
Jolly Drapion @ Scope Lens
Ability: Sniper
EVs: 252 Atk, 4 Def, 252 Spe
Cross Poison
Earthquake
Ice Fang
Night Slash
I think this is the one of the default movesets given at smogon, meant to exploit Sniper Ability. Cross Poison and Night Slash are STAB and both have high CH ratios. Ice fang deals with ground types and Earthquake is there for type coverage.
Adamant Toxicroak @ Life Orb
Ability: Dry Skin
EVs: 4 HP, 252 Atk, 252 Spe
Cross Chop
Sucker Punch
Swords Dance
Taunt
Taunt and Sucker Punch go together to ensure Sucker Punch's success. Swords Dance is pretty self explanitory and Cross Chop is a good STAB move.