What was Paul Klee uncle's name?

Paul Klee's uncle's name was Ernst Frick, brother to Paul's mother, Ida Frick.

Interesting tidbit: Ernst owned a café. As a child, Paul Klee liked to visit his uncle's café where the tables were made of polished marble. The ground marble design on the tables, as well as the contrasting marbled plates, inspired Klee's penchant for the bizarre. In fact, he was only four years old when he began doodling representations of what he called "evil spirits."