The "comedic lolicon" or "comedic shotacon" is a particular type of pedophilic character (a lolicon targets girls, and a shotacon, boys) most commonly found in Japanese Media. The names are derived from Lolicon and Shotacon.
Sometimes, a work's creator wishes to overlook the damaging aspect of pedophilia and use a pedophile character for comedic purposes. Therefore, rather than being played to repulse the audience, a lolicon or shotacon in mainstream works is normally treated as being a little creepy, but ultimately harmless. Because of Western media views, you are highly unlikely to see a lolicon or shotacon outside of Japan-derived works; while Western media can and will use pedophilia for jokes, it tends to contain stronger elements of Black Humor. Note that the terms do not refer to any pedophile regardless of portrayal, nor does the existence of this trope imply that the Japanese are more approving of pedophilia.
Compare/contrast Pædo Hunt for portrayals of pedophilia as a villainous trait, and Mistaken for Pedophile for false allegations of pedophilia being Played for Laughs. The Japanese fashion style called "Lolita" and our trope Elegant Gothic Lolita are only tangentially related.