Maiamai Children

The Maiamai Children is the name used to refer to Mother Maiamai's 100 Maiamai children. They debuted in The Legend of Zelda: A Link Between Worlds where they serves as the main optional collectible of the game.

The Legend of Zelda: A Link Between Worlds
The Maiamai children followed Mother Maiamai during her interdimensional travels through Hyrule and Lorule but were lost in the process while Mother Maiamai was walled into a Hyrulean cave by someone who had mistaken her for a monster. After Link met Mother Maiamai and accepted helping her finding her children, he will obtain a map that separate both worlds into sections with the number of remaining Maiamai Children in each sections mentioned on the map.

Mother Maiamai will upgrade one of its owned weapons for every 10 children Link saves. They are generally hidden and Link can know one is near as they are constantly squeaking. Link will also turn his head and stare towards a nearby Maiamai's location. Maiamai Children are only found on the overworld however. Link will usually need specific abilities to find some like the Wall Merging for the ones stuck to walls or the Pegasus Boots for the ones hidden in trees or atop pillars, etc... After all Maiamai have been found, Link's Spin Attack ability will be upgraded to the Great Spin, and Mother Maiamai will leave her cave with her children to a different dimension. A single female Maiamai child is left behind in the cave, declaring herself as the 72th Maiamai Children saved by Link say she stayed behind to become her own Maiamai and wish to becomes a good mother like Mother Maiamai was to her.

Trivia

 * The 72th Maiamai may be a hint to The Legend of Zelda: Majora's Mask 3D, which was in development at the time as the game is known for its 72 hours time limit.
 * This would also not be the only Majora's Mask reference in the game as the Majora's Mask itself can be found in Link's House without an explanation in this game.