Did you know that there is an entire shark genus named gollum? The gollumshark (or slender smooth-hound) is one of three species of this genus, and it was reasoned that “this shark bears some resemblance in form and habits” with the The lord of the rings character.

Gollum attenuatus macauley1.jpg
Von Hawaii Undersea Research Laboratory – http://www.fishbase.us/photos/thumbnailssummary.php?ID=5921#, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=14941704

The gollumshark lives in the deep sea around New Zealand at depths of 980–1,970 ft -300–600 m-. It has a very thin body, big eyes and a broad, flattened head with a long, distinctively bell-shaped snout. It grows up to 3.6 ft -1.1 m- in length and 8.8 lb -4 kg- in weight.

Gollumsharks reach sexual maturity at approximately 28 in -70 cm- long. Females have got two uteri, their inner surface is covered by villi. They produce an uterine secretions called histotroph, which is used to feed the embryos (one in each uterus). Gollumsharks are ovoviviparous, but in a very specialized form: the females produce a single capsule in each uterus that contains 30–80 ova, but only one of them is fertilized and develops into an embryo that consumes the rest of the ova (oophagy) and stores the yolk material in its external yolk sac. When the embryo is 1.1–1.6 in -29–40 mm- long, it emerges from the capsule and uses up its external yolk sac and feed additionally from the histotroph. The embryo is born at 13–17 in -34–42 cm- length.

Sources: here, here and here