The earliest cartoons that get close to referencing Wilde are cartoons criticizing Aestheticism. This is one of the earliest examples. The title of this cartoon, "Nincompoopiana---The Mutual Admiration Society," is a clear poke at the validity of Aestheticism: "Nincompoopiana" seems to refer to some level of nonsensical behavior, and the "Mutual Admiration Society" appears to be making fun of Aestheticists' ideas of beauty: this cartoon views Aestheticism as mostly skin-deep, and full of too much admiring of surfaces, if you will. The dialogue occurring underneath the title of the cartoon is between Our Gallant Colonel "(who is not a Member [of the Mutual Admiration Society] thereof)" and Mrs. Cimabue Brown "...who is)." They're talking about a (fictional) poet named Jellaby Postlethwaite, who seems to express all the qualities of a stereotypical gay male æsthete. At the end of the dialogue, Mrs. Cimabue Brown says the following: "Oh, look at [Jellaby's] Grand Head and Poetic Face, with those Flowerlike Eyes, and that Exquisite Sad Smile! Look at his Slender Willowy Frame, as yielding and fragile as a Woman's!" This description of Jellaby could very well also apply to Oscar Wilde, especially with terms such as "Flowerlike Eyes" and "Slender Willowy Frame, as yielding and fragile as a Woman's!" Attributing æsthete men to flowers is a pattern that repeats throughout the timeline, whether literally (think 1882-1883) or metaphorically (think of the signs of homosexuality that Wilde exhibited from 1890-1895).

Sources: 

Du Maurier, George Louis. "Nincompoopiana---The Mutual Admiration Society." Punch Magazine, 14 Feb. 1880, p. 66.

Du Maurier, George Louis. "Nincompoopiana." Harvard Museum, https://harvardartmuseums.org/collections/object/298491.