Are you ready for things to get REALLY weird?! Playing the game in the typical, recommended order, you'll fight your way through a whole lot of beasts and screwed-up villagers before you encounter your first kin, a category of enemies characterized by their mollusk-like features and...waaait a minute...silvery, white blood?! Funny coincidence I guess! Don't worry about it!

The Brainsucker resembles an emaciated, translucent white humanoid with no trace of ears, shallow holes for eyes and a vertical, gaping pit where its mouth and nose should be, erupting with an assortment of wormy tentacles. It's obviously quite a bit like the Illithids or Mind Flayers from Dungeons and Dragons, and you know from its name that it has the same dietary requirements. This means that it not only does quite a bit of damage, but even steals some of your insight!

...But while mind flayers suck brains with only their oral tentacles, the Bloodborne Brainsucker pulls a fast one; it sucks your brain with ONE BIG squirmy appendage that pops out from the back of its head! This appendage actually looks and moves remarkably like a giant flatworm, actually, such as a planarian or a parasitic fluke.

In this closeup shot by youtube's always helpful Zullie, you can see that the brainsucker is more than just some alien humanoid with a natural head-slorping proboscis. The "flatworm" erupts from a sewn-up surgical wound on the top of its skull, actually breaking the stitches in the process and never actually seen retracting again; once it bursts out, the sucker just keeps walking around with its big wiggly worm-hat. So, that's something put there artificially, which probably means these creatures used to be people. Who would do that? Why? And how??

One clue is in the item Madman's Knowledge, the quickest way to increase your own insight. It's depicted by a pale wisp of vapor curling up from a broken human skull, but that vapor has two little prong on the top end, like the outline of a slug with two eyestalks.

"Great One's Wisdom" makes it clear that this resemblance is meaningful, since this skull is erupting with a whole mass of these wisps, and they all have those same two stalks.

Another item in the game is Pearl Slug, and these are just fully corporeal, adorable little grey-blue garden slugs! Apparently these actually come from the chalice dungeons, the description reading: "Of the all the strange lifeforms that reside in the nooks and crannies of the old labyrinth, the slugs are clear signs of the left-behind Great Ones." There's that phrase again, the Great Ones!

The "empty phantasm shell" is an item you can retrieve from none other than Byrgenwerth college, where Professor Genius spread the word of More Eyes. Part of this one's description reads: "Empty invertebrate shell that is said to be a familiar of a Great One. The Healing Church has discovered a great variety of invertebrates, or phantasms, as they are called."

Is this implying that, in the world of Bloodborne, soft-bodied invertebrates in general are referred to as "phantasms?" Or only certain invertebrates? Apparently such creatures are "familiars" to the "Great Ones."

Another item you can find at the college is "Augur of Ebrietas," which is just one large gooey blue slug! This one says "Remnant of the eldritch Truth encountered at Byrgenwerth. Use phantasms, the invertebrates known to be augurs of the Great Ones, to partially summon abandoned Ebrietas. The initial encounter marked the start of an inquiry into the cosmos from within the old labyrinth, and led to the establishment of the Choir."

This early in the game, you don't know who or what Ebrietas is, but this item allows you to unleash a bunch of tentacles as an attack! But who are "The Choir?" Actually the most powerful and highest ranking branch of the Healing Church! While the rest of the church obsessed over the nasty dog blood, the Choir took more interest in all that cockamamie eyeball business, and believed in furthering the evolution of all humanity. We still haven't even looked at every "phantasm" item in this game, either! But what do these specifically mean for the Brainsucker?

I guess the answer is fairly obvious; the Choir thought "phantasms" could somehow bring human beings closer to the "Great Ones," and conducted all manner of experiments with the poor little sluggies, even planting them inside human subjects just to see what would happen. In the case of the Brainsucker, what happened was that the human host simply degenerated while the implant became an out of control, brain-hungry predator; not at all the ascended god-being the Choir probably hoped for, and these experiments either escaped or were abandoned to their own devices.