Japan: The Very Hungry Caterpillar (2018)

Used on a Card with Special Postmark:

Alderney: A Christmas Carol (2018)

Guernsey: The Nutcracker and the Mouse King (2018)

[Appendix] Ireland: Elf on the Shelf (2018)

On a matching Card:

Spain: Harry Potter (2018)

United Kingdom: Harry Potter (2018)

Used on Cards:

[Appendix] Portugal: Mickey Mouse (2018)

Used on a Card:

Japan: Posukuma meets Kumamon (2018)

Nothing else needed.

On a matching Card with Special Postmark:

Used on Card with Special Postmark:

Switzerland: Fairy Tales (2018)

Sheetlets:

FDC:

Australia: Children's Bush Classics (2018)

Maxicards:

[Appendix] Japan: Winnie the Pooh (2018)

Used on a Card with Special Postmark:

USA: Scooby-Doo (2018)

Used on a Card with Special Postmark:

Used on a Cover:

Germany: Fix and Foxi Special Postmark (2018)

Moldova: Guguta for Postcrossing (2018)

Poland: Proszę słonia (2018)

FDC:

Used on a Card: