Bookworm

If Fang Yuan had a Bookworm, he could feed a map to it and recall that map clearly forever, as long as he did not lose the Gu. Its value sits close to the Liquor worm and White Boar Gu. All three are rare rank one species, expensive on the market, and often sold out in moments. ^{ch. 71}

In his previous life Fang Yuan did not obtain the Liquor worm or White Boar Gu. He accidentally obtained a Bookworm. That copy advanced ranks with him and accompanied him for sixty years. In the current life he craves another, then sets the wish aside because Bookworms are rare and low in number. ^{ch. 71}

After killing the demonic Gu Master Chen Cui Hua, Fang Yuan finds a Bookworm in her smashed brain matter. Bai Ning Bing’s attack has already killed it. Fang Yuan judges that this Bookworm was the inheritance item whose information taught her about Gu Masters, including secret recipes. ^{ch. 211}

It is like a silkworm. It has a head, body, and stomach as three distinct parts, yet overall it looks like a cocoon, round and cute. The body is white, with a layer of enamel on the surface that gives an oily glow. Held in the hand it is round and smooth, like a high grade porcelain vase. ^{ch. 261}

It is a storage type Gu. The Tusita flower stores physical items. Bookworm stores knowledge and information. If it is destroyed, it explodes into a flash of harmless white light. Injecting primeval essence turns it into a flash of white light that enters the forehead, between the eyebrows, and plants the stored information as content the user has memorised. It is precious and as rare as the Liquor worm, with demand and almost no supply once one appears. In Tong Ou shop Fang Yuan browses two copies lent by the elderly clerk, then returns them. ^{ch. 261}

In Shang clan city’s Tong Ou shop the listed price is six hundred primeval stones, slightly above a Liquor worm at five hundred eighty, matching black and white boar Gu at six hundred, against about two hundred fifty for ordinary rank one Gu. ^{ch. 262}

Lang Ya land spirit hands Fang Yuan a Bookworm emanating rank three aura. Fang Yuan has seen Bookworms before as valuable rank one Gu. Lang Ya’s previous self broke the limits of the rank one Bookworm and developed rank two and rank three versions. Fang Yuan does not own this copy. He borrows it from Lang Ya land spirit and reads three true inheritances stored inside. ^{ch. 1051}

In a later Ren Zu telling, an inkman elder says there are many bookworms on Book Mountain that record knowledge left by inkman seniors. Ren Zu gathers those bookworms for information, then with cognition Gu refines more knowledge from them. ^{ch. 2161}