The surname

Neue Kronik von Böhmen (1780)
A passage on page 116 gives an explenation of the Katzer surname origin
(see translation below)

Crowned by Bohemia Siegmund now made every effort to conquer Prague. As you could experience this in the city, you were armed for brave resistance. Everything that was only able to carry arms was ready for the freedom of its religion to shed its blood the women showed themselves as heroines and followed the brave examples of their husbands. The Hussites‘ weapons were mostly skewers and iron flails. Zizka took possession of Mount Witkow, where he fortified himself to the best and ridiculous ha! ha! ha! Huss! Huss! Huss! Katzer! Katzer! Katzer! shouted at where a Prague came into your hands they burned, among which some innocent people would have been burned if not those Bohemian gentlemen who were with the Emperor’s army had saved them because they Germans all Bohemia considered heretics The Hussites of their part b not guilty of this maltreatment, the captured Germans put them in spilled beer kegs and burned them in the face of their enemies on the ramparts

Jan Huß (John Huss) – Council of Constance 1415 – the beginning of Katzers.

Czech (Kačer), Slovak (Káčer): from Czech kačer ‘drake’, probably applied as a nickname for someone with some fancied resemblance to a drake. Hungarian (Kaczér): nickname from kaczér ‘immoral’, ‘narcissistic’, ‘seductive’. Katzer derivative of the Old High German personal name Cazo, of uncertain origin. Silesian (also kether, ketzer, katzer): from Middle High German ketzer ‘heretic’, ‘freethinker’, ‘sodomite’. Germanized form of Serbian kacor ‘drake’.

Nicolas Katzer (Ketzer)
the court astronomer of Henry VIII (king of England)
is the oldest certified person by the name of Katzer (Ketzer) we know.
Portrait was painted in 1528 by Hans Holbein Jr.