I may have a bit of a weakness for Loki with his kids. Okay, a HUGE weakness. And, really, it may be for all Supervillains with their children cause I always had a major thing for Lex being cute with Kon when I was in SV, hmmm...^__-
Alas, as popular as preggers!Loki is, him with his kids doesn't seem as common in fic...:-p
Not in the comics, but traditional Norse myth, Loki, who was a master at shape-shifting, among other things, disguised himself as a mare to distract a stallion as part of a bet and had a child in that form, Sleipnir. He then gifted his child to Odin to be his steed. Ahh, norse myth! ^__^