List of Pokémon forms by release date/2017

February
Main release of Johto-region. 84 Pokémon species including 26 forms of Unown were released, one for each letter of the alphabet. Johto Silver and Gold  medals became achievable for the first time.

Regular (109) =

March
First shiny Pokémon Magikarp was released at the start of Water Festival 2017.

Shiny (2) = PS Magikarp PS Gyarados

July
Articuno and Lugia were released as Raid Bosses at the start of Pokémon GO Fest 2017

Regular (2) =

July
Moltres was released as a Raid Boss.

Regular (1) =

August
Zapdos was released as a Raid Boss.

Regular (1) =

August
Shiny Pikachu family was released at the start of Pokémon GO Park.

Shiny (3) = PS Pikachu PS Raichu PS Pichu

August
Mewtwo was released as a Raid Boss at the start of Pokémon GO Stadium.

Regular (1) =

August
Raikou, Entei and Suicune were released as Raid Bosses. They were exclusive to following regions in the first month: Raikou could be battled throughout the Americas. Entei could be battled throughout Europe and Africa. Suicune could be battled throughout the Asia-Pacific region.

Regular (3) =

October
Release of Hoenn-region Halloween-themed Pokémon at the start of Halloween 2017. Shiny Sableye was released. Hoenn-region Pokédex introduced 135 new Pokémon species, 148 distinct regular forms and 145 distinct shiny forms. Hoenn Bronze medal became achievable for the first time.

Regular (5) =

Shiny (1) = PS Sableye

October
Shiny form of Duskull was released at the start of the seventh day of Halloween 2017.

Shiny (2) = PS Duskull PS Dusclops

October
Shiny form of Shuppet was released at the start of the twelfth day of Halloween 2017.

Shiny (2) = PS Shuppet PS Banette

November
Ho-Oh was released as a Raid Boss.

Regular (1) =

December
Main release of Hoenn-region. Shiny Absol and Mawile were released. Hoenn Silver medal became achievable for the first time.

Regular (50) =

Shiny (2)= PS Mawile PS Absol

December
Groudon was released as a Raid Boss.

Regular (1) =

December
Release of Hoenn-region Aquatic-themed Pokémon at the start of Holiday 2017. Delibird and shiny Snorunt were released.

Regular (21) =

Shiny (2)= PS Snorunt PS Glalie