Simplify the following text for a Grade 6 native English-speaking person.
Original: John Stig Claesson ( June 2 , 1928 â `` January 4 , 2008 ) , also known under his signature Slas , was a Swedish writer , visual artist , and illustrator .
Simplified: John Stig Claesson ( June 2 , 1928 -- January 4 , 2008 ) was a Swedish writer and illustrator . He also was known by his signature Slas .