Lee Sang-moo, a South Korean cartoonist who created a popular baseball character in the 1970s, died of a heart attack while working in his Seoul studio on Sunday. He was 70.

He began his career under his birth name, Park No-cheol, in 1963, with comic strips in a regional newspaper in Daegu, some 300 kilometers southeast of Seoul. Three years later, he moved to Seoul and began publishing a serial in a comic magazine under his pen name, Lee Sang-moo.

The late cartoonist was best known for Dokgo Tak, an iconic baseball pitcher and a "Little Engine That Could" type of character. The diminutive hurler with a chip on his shoulder -- he wore a disguise to fool his disapproving dad and get on the mound -- was a breath of fresh air among comic readers who'd grown weary of pretty-faced, ebullient characters.

Dokgo Tak made his first appearance in 1971, and was the main figure in a handful of later works centered on his adventures on and off the field.

Dokgo Tak's heyday also coincided with the launching of the country's top professional baseball league in 1982, and fans identified the character with some imaginative, at times outlandish, pitches that he threw at opposing hitters.

In the 1990s, Lee stuck with sports and published a series of golf cartoons.

Lee is survived by his wife and daughter. (Yonhap)