From the Super Mario Wiki
A Blooper Nanny (initially known as Bloober with kids) is a Blooper with Blooper Babies that first appeared in Super Mario Bros. 3.
Super Mario series
Super Mario Bros. 3
In Super Mario Bros. 3, she begins to glow when approached and her kids will "explode" away from her making it harder to swim. More kids appear a few seconds later. Just like normal Bloopers, they follow Mario in an attempt to hurt him.
New Super Mario Bros.
Two Blooper Nannies appear in a bonus room of 3-3 in New Super Mario Bros. This time, they will flash rainbow instead of glowing.
New Super Mario Bros. Wii
Blooper Nannies later appear in New Super Mario Bros. Wii in World 4-4. Now, instead of flashing at all, the Blooper Babies will circle around the Blooper Nanny before dispersing.
New Super Mario Bros. 2
Blooper Nannies make their least common appearance in World 3-5 of New Super Mario Bros. 2.
New Super Mario Bros. U
Blooper Nannies also reappear in New Super Mario Bros. U in the secret level Blooper's Secret Lair. This is their second least common appearance.
They are one of the few enemies that don't appear in New Super Luigi U.
Super Mario RPG: Legend of the Seven Stars
Only one appears in the Sunken Ship during the events of Super Mario RPG: Legend of the Seven Stars, and oddly touching her or any of her babies results in a normal battle with only one Blooper.
The Adventures of Super Mario Bros. 3
Blooper Nannies made occasional appearances on The Adventures of Super Mario Bros. 3, where they served as aquatic nuisances to Mario and Luigi.
Nintendo Adventure Book
In the Nintendo Adventure Book Leaping Lizards, two Blooper Nannies (known here as "Bloober Nannies") compete in the International Mushroom Games as members of a team known as the Sneaks. What events they participate in besides the Beetlebowl, an all-team game, are unspecified.
Names in other languages