This video wouldn't let me embed it but seriously check out this video! the second half shares the story of the female sea louse, which, once impregnated, remains a captive of the male in his underwater dungeon until she gives birth. Unfortunately, she never lives to see mother's day because her children eat her from the inside out while they develop, eventually swimming free of her empty carcass. Gruesome.
Here is the link: (embedding is disabled on the video but still, CHECK IT OUT!)