Hey guys, I've looked over my movepool and made a few changes, here you go:
Level Up moves
TM moves
Move Tutor moves
Egg moves
Notable Inclusions
Notable Exclusions
Closing thoughts
Level Up moves
HS. Fire Fang
HS. Ice Fang
HS. Thunder Fang
1. Bite
1. Encore
5. Sandstorm
10. Screech
14. Endure
19. Mud Bomb
23. Scary Face
28. Thrash
34. Take Down
41. Horn Drill
47. Crunch
54. Earthquake
70. Moonlight
HS. Ice Fang
HS. Thunder Fang
1. Bite
1. Encore
5. Sandstorm
10. Screech
14. Endure
19. Mud Bomb
23. Scary Face
28. Thrash
34. Take Down
41. Horn Drill
47. Crunch
54. Earthquake
70. Moonlight
TM moves
TM01: Focus Punch
TM02: Dragon Claw
TM03: Water Pulse
TM05: Roar
TM06: Toxic
TM10: Hidden Power
TM11: Sunny Day
TM12: Taunt
TM13: Ice Beam
TM15: Hyper Beam
TM17: Protect
TM18: Rain Dance
TM21: Frustration
TM23: Iron Tail
TM26: Earthquake
TM27: Return
TM28: Dig
TM31: Brick Break
TM32: Double Team
TM35: Flamethrower
TM37: Sandstorm
TM38: Fire Blast
TM39: Rock Tomb
TM41: Torment
TM42: Facade
TM43: Secret Power
TM44: Rest
TM45: Attract
TM52: Focus Blast
TM56: Fling
TM58: Endure
TM59: Dragon Pulse
TM65: Shadow Claw
TM66: Payback
TM68: Giga Impact
TM71: Stone Edge
TM72: Avalanche
TM78: Captivate
TM79: Dark Pulse
TM80: Rock Slide
TM82: Sleep Talk
TM83: Natural Gift
TM87: Swagger
TM90: Substitute
HM01: Cut
HM04: Strength
HM06: Rock Smash
HM08: Rock Climb
TM02: Dragon Claw
TM03: Water Pulse
TM05: Roar
TM06: Toxic
TM10: Hidden Power
TM11: Sunny Day
TM12: Taunt
TM13: Ice Beam
TM15: Hyper Beam
TM17: Protect
TM18: Rain Dance
TM21: Frustration
TM23: Iron Tail
TM26: Earthquake
TM27: Return
TM28: Dig
TM31: Brick Break
TM32: Double Team
TM35: Flamethrower
TM37: Sandstorm
TM38: Fire Blast
TM39: Rock Tomb
TM41: Torment
TM42: Facade
TM43: Secret Power
TM44: Rest
TM45: Attract
TM52: Focus Blast
TM56: Fling
TM58: Endure
TM59: Dragon Pulse
TM65: Shadow Claw
TM66: Payback
TM68: Giga Impact
TM71: Stone Edge
TM72: Avalanche
TM78: Captivate
TM79: Dark Pulse
TM80: Rock Slide
TM82: Sleep Talk
TM83: Natural Gift
TM87: Swagger
TM90: Substitute
HM01: Cut
HM04: Strength
HM06: Rock Smash
HM08: Rock Climb
Move Tutor moves
Ancientpower
Aqua Tail
Block
Earth Power
Endeavor
Fury Cutter
Headbutt
Iron Head
Mud-Slap
Outrage
Snore
Spite
Superpower
Aqua Tail
Block
Earth Power
Endeavor
Fury Cutter
Headbutt
Iron Head
Mud-Slap
Outrage
Snore
Spite
Superpower
Egg moves
Assurance (Raticate, Persian, Primeape, Umbreon, Girafarig, Donphan, Mightyena, Rampardos, Weavile)
Rapid Spin (Blastoise, Sandslash, Donphan, Torkoal)
Ice Shard (Dewgong, Lapras, Weavile, Mamoswine, Abomasnow)
Double-Edge (Venusaur, Raticate, Marowak, Typhlosion, Donphan, Delcatty, Aggron, Spinda, Hippowdon)
Fissure (Dugtrio, Camerupt, Hippowdon)
Pursuit (Raticate, Tauros, Umbreon, Dunsparce, Sceptile, Zangoose, Rampardos, Floatzel)
Rapid Spin (Blastoise, Sandslash, Donphan, Torkoal)
Ice Shard (Dewgong, Lapras, Weavile, Mamoswine, Abomasnow)
Double-Edge (Venusaur, Raticate, Marowak, Typhlosion, Donphan, Delcatty, Aggron, Spinda, Hippowdon)
Fissure (Dugtrio, Camerupt, Hippowdon)
Pursuit (Raticate, Tauros, Umbreon, Dunsparce, Sceptile, Zangoose, Rampardos, Floatzel)
Notable Inclusions
Aqua Tail gives Colossoil a solid coverage attack to smack around other bulky Ground types a fair bit.
Elemental Fangs are very good moves, thanks to nice coverage when paired with STAB Ground.
Flamethrower/Fire Blast prevent Colossoil from being walled by Skarmory, hitting it on its weaker special side.
Ice Shard is a nice move to have, picking off faster foes, as well as Gliscor.
Crunch is fairly self-explanatory.
Earthquake is too.
Pursuit makes Colossoil quite the fine trapper.
Stone Edge is on just about every Ground-types movepool.
Focus Punch can be used with Substitute and Colossoil's high Attack to make a fearsome SubPuncher.
Superpower packs awesome coverage with STAB Dark attacks.
Taunt is on every Pokemon's movepool, but Colossoil can outspeed most secondary users and Taunt them to prevent them from using non-damaging moves.
Torment is also found on every Pokemon's movepool.
Rest and Sleep Talk help Colossoil tank more reliably than Moonlight.
Rapid Spin eliminates entry hazards, common secondary moves.
Toxic is required for all.
Substitute is a great move for Colossoil, thanks to that monstrous HP stat.
Moonlight isn't exactly reliable, but it's good enough. Colossoil is very bulky, and it'll be a shame to waste that bulk.
Encore discourages secondary moves, as a Pokemon may get locked into a secondary move and give a free turn.
Elemental Fangs are very good moves, thanks to nice coverage when paired with STAB Ground.
Flamethrower/Fire Blast prevent Colossoil from being walled by Skarmory, hitting it on its weaker special side.
Ice Shard is a nice move to have, picking off faster foes, as well as Gliscor.
Crunch is fairly self-explanatory.
Earthquake is too.
Pursuit makes Colossoil quite the fine trapper.
Stone Edge is on just about every Ground-types movepool.
Focus Punch can be used with Substitute and Colossoil's high Attack to make a fearsome SubPuncher.
Superpower packs awesome coverage with STAB Dark attacks.
Taunt is on every Pokemon's movepool, but Colossoil can outspeed most secondary users and Taunt them to prevent them from using non-damaging moves.
Torment is also found on every Pokemon's movepool.
Rest and Sleep Talk help Colossoil tank more reliably than Moonlight.
Rapid Spin eliminates entry hazards, common secondary moves.
Toxic is required for all.
Substitute is a great move for Colossoil, thanks to that monstrous HP stat.
Moonlight isn't exactly reliable, but it's good enough. Colossoil is very bulky, and it'll be a shame to waste that bulk.
Encore discourages secondary moves, as a Pokemon may get locked into a secondary move and give a free turn.
Notable Exclusions
Drill Peck has an ass typing and most Fighting types are hit just as hard by Earthquake.
Zen Headbutt for the same reason as Drill Peck.
I don't see the viability of U-turn, Colossoil doesn't seem like prime scouting material.
What good is Megahorn? It usually hits as hard as Crunch, and the only Grass types seen in OU are Celebi, who wouldn't switch in on Colossoil anyway, and Breloom, who goes down to Fire and Ice moves.
imo, Seed Bomb would make this thing way too broken, bulky waters should be a good Colossoil counter.
Selfdestruct doesn't look very useful at all, Colossoil can usually take down most things through brute force, it doesn't need to go boom.
Sucker Punch would encourage secondary moves, kinda defeats the purpose, doesn't it?
Considering we've got Auto-Magic Coat and Guts to work with, I don't think Heal Bell would be that useful.
Fake Out is used mainly to stop the opponent from using certain moves, but since they'll most likely be secondary moves, Taunt will acheive the same results.
Zen Headbutt for the same reason as Drill Peck.
I don't see the viability of U-turn, Colossoil doesn't seem like prime scouting material.
What good is Megahorn? It usually hits as hard as Crunch, and the only Grass types seen in OU are Celebi, who wouldn't switch in on Colossoil anyway, and Breloom, who goes down to Fire and Ice moves.
imo, Seed Bomb would make this thing way too broken, bulky waters should be a good Colossoil counter.
Selfdestruct doesn't look very useful at all, Colossoil can usually take down most things through brute force, it doesn't need to go boom.
Sucker Punch would encourage secondary moves, kinda defeats the purpose, doesn't it?
Considering we've got Auto-Magic Coat and Guts to work with, I don't think Heal Bell would be that useful.
Fake Out is used mainly to stop the opponent from using certain moves, but since they'll most likely be secondary moves, Taunt will acheive the same results.
Closing thoughts
Colossoil is essentially a versatile offensive threat for the most, due to its wide variety of offensive options that have excellent type coverage. While it does have non-damaging options available, they are mostly self-support and its other support options are normally better done by something else.