Magcargo
Magcargo is almost exactly the height of Azumarill.
POKÉMON · HEIGHT & WEIGHT
Azumarill is 80 cm (2 ft 7 in) tall and weighs 28.5 kg (63 lb).

Pokémon names and artwork © Nintendo, Creatures Inc. and GAME FREAK inc. Size It Up is an unofficial fan project and is not affiliated with or endorsed by them. Image source ↗
An average adult stands about 175 cm, so Azumarill is about 46% of the height of a grown-up.
Of the 127 Pokémon entries measured on this site, Azumarill ranks 71st by height.
Magcargo is almost exactly the height of Azumarill.
Jumpluff is almost exactly the height of Azumarill.
Flaaffy is almost exactly the height of Azumarill.
This page.
Aromatisse is almost exactly the height of Azumarill.
Aipom is almost exactly the height of Azumarill.
Tyrogue is a little shorter than Azumarill.
See all 127 Pokémon sizes, smallest to largest
Numbers are easy to read and hard to picture. In Size It Up you drag a mystery object until it looks right next to a reference drawn at true scale, then the reveal shows how close you came. Azumarill turns up in the daily puzzle at random, and the Pokémon practice set deals five Pokémon at a time.
Measurements are the canon figures listed on the Pokémon Wiki (Fandom) page for Azumarill ↗. Where a character has several forms, the size above is for the form shown in the artwork.