Who is the fastest Pokémon with Sleep Talk as well as a phazing move (Whirlwind, Roar, etc.)?

Question

Title says it all.

Answer 1

Gen 8 Update

The following Pokemon are the fastest Pokemon that can learn Sleep Talk and Roar:
Sleep Talk + Roar:
Tapu Koko, Aerodactyl, and Jolteon: base 130 speed(non megas)
Mega Aerodactyl with a base 150 speed(if megas count)
Sleep Talk + Whirlwind
Crobat and Aerodactyl with base 130 speed (non megas)
Mega Aerodactyl with base 150 speed (if megas count)
Sleep Talk + Dragon Tail
Dragapult with a base 142 speed
Sleep Talk + Circle Throw
Lopunny with a base 105 speed (without megas)
Mega-Lopunny with a base 135 speed (if megas count; also has Scrappy, meaning it can hit ghost types)

Other options for Sleep Talk + Roar, Whirlwind, Dragon Tail, etc:

Sleep Talk + Roar:
Jolteon with a base 130 speed that can gain a 50% speed boost with Quick Feet
If you use a Pranskter Riolu that knows Sleep Talk and Roar and Sleep Talk lands on Roar, Roar can have +1 priority.
Sceptile with a base 120 speed that has the ability Unburden activated.
Mega-Swampert with a base 70 speed with Swift Swim taking effect. Floatzel with a base 115 speed with Swift Swim taking effect.
Sleep Talk + Whirlwind:
Shiftry with a base 80 speed with Chlorophyll taking effect.
If you use a Pranskter Murkrow with Sleep Talk and Whirlwind, and Sleep Talk Lands on Whirlwind, Whirlwind can have +1 priority.
Sleep Talk + Dragon Tail
Drednaw with a base 74 speed with Swift Swim taking effect.
Dracozolt with a base 75 speed with Sand Rush taking effect.
Sleep Talk + Circle Throw:
If you use Prankster Riolu with Sleep Talk and Circle Throw and Sleep Talk lands on Circle Throw, Circle Throw can have +1 priority.
Poliwrath with a base 70 speed with Swift Swim taking effect.

Source: Adding filters on who can learn Sleep Talk, Whirlwind, Roar, Dragon Tail, Circle Throw, and other filters on the Showdown Teambuilder

Answer 2

Here is the fastest ones:

    Sleep Talk+Roar=           Linoone or Slaking with 100 Speed
    Sleep Talk+ Whirlwind=     Hippowdon with 47 Speed
    Sleep Talk+ Dragon Tail=   Lickilicky with 50 Speed

I also included the Sleep Talk+Dragon Tail combo since they fulfil the same purposes. Other options include that learn Sleep Talk+Roar are:

Darmanitan  95 
Vigoroth    90
Ursaring    55, can double its speed via Quick Feet
Beatric     50, doubled in the Rain with Swift Swim

Comments

Thanks a lot Flaaffy!

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Glad to help!