I dont know the exact origin for certain but i can say that it began to be widely circulated around the 1900s as sort of a a fear tactic by the media of the time to capitalise on the fear of the Chinese immigrants by the working/middle class since they were taking jobs for cheaper wages than their European counterparts. Also their customs and language was radically different which inspired distrust.

http://www.sjsapush.com/resources/ce_witness_2_lg.jpg

http://thesocietypages.org/socimages/2008/07/08/old-yellow-peril-anti-chinese-posters/

http://picturinghistory.gc.cuny.edu/images/WildBeast-hires.png

http://sunsite.berkeley.edu/cic/images/brk00001484_16a_j.jpg

http://phdsandpigtails.files.wordpress.com/2014/01/yellow-peril.jpeg?w=615

Basically they were emphasizing what was different about the Chinese i.e. eyes, bone structure and body structure to create a caricature which was highly memorable.