I actually believe he meant a cockatoo, called kakadu in German.
yes "kakadu" in german, so i learned the english word for it today, thanks oren helpful as always
they are white and bear a kind of crown (crest) that is normally retracted which is when they look like the upthread image in question, gonna find an image now
EDIT: found :-)
A cockatoo is a parrot that is any of the 21 species belonging to the bird family Cacatuidae, the only family in the superfamily Cacatuoidea. Along with the Psittacoidea and the Strigopoidea, they make up the order Psittaciformes. Wikipedia
Scientific name: Cacatuidae
Higher classification: Parrot
Lifespan: Cockatiel: 10 – 14 years, Galah: 40 years, MORE
Mass: Cockatiel: 3.2 oz, Galah: 11 oz, MORE Encyclopedia of Life
Length: Cockatiel: 12 – 13 in., Sulphur-crested cockatoo: 20 in., White cockatoo: 18 in., Major Mitchell's cockatoo: 20 – 24 in. Encyclopedia of Life
Did you know: The cockatiel is about 32 cm (13 in) long and is by far the smallest and lightest
cockatoo. wikipedia.org
german (plural)
https://de.wikipedia.org/wiki/Kakadus