The Bone Clam is first encountered in Hana Valley, in a cave that is a part of the valley's underground cave network. The Bone Clam has a blue shell filled with skulls inside, an eyeball with a purple and black iris. It has a system of muscles and tendons attached to the back of the shells, acting as a mean of manipulating the movements of the shell pieces. Also, two arms sprouted from this mass of flesh, and these arms were used as both a mean of movement and offense, as the Bone Clam can use its arms as "legs", and run around on them.
The Bone Clam is a demon which enjoys the gruesome and agonizing process of clamping its shell on the legs of swimmers and pulling them down, drowning them, and then slowly crunching their bones. Sometimes, they also scavenge the dry land due to hunger.
"This creature enjoys on clamping down on the legs of swimmers, drowning them, and then slowly crunching their bones. Sometimes their hunger sends them scampering for dry land. They are quite vulnerable on the inside, 'provided you can pry open their shell."
The Bone Clam is quite easy to take out and farm. First, Chibiterasu has to damage the demon until it is stunned. Use any class of Divine Instruments, but Glaives are recommended for their heavy hits, but this is only possible later into Chibiterasu's journey. The Providence Crystal is an even better choice, as the Bone Clam is vulnerable to fire (as it is somehow linked to water or ice, seeing that it releases a water crystal when opened. Also, ice won't work on this demon). Lightning is also nice, but Chibiterasu may end up accidentally killing the Bone Clam before he has a chance to farm it. After sufficient damage has been dealt, the Bone Clam will be stunned, which then prompts Chibiterasu to use Bloom and open the pieces of the shell, revealing the vulnerable mass of flesh inside. Attack it until it has some stamina left (about a quarter or one fifth of the original stamina), then use Power Slash to deal the killing blow, earning Chibiterasu a Demon Bone. If Chibiterasu is using the Providence Crystal, then only use normal shots (neutral element) to take down the Bone Clam's stamina, as elemental attacks will most likely kill it. Note that Power Slash must be used to deal the final killing blow to the Bone Clam, not after it had entered the dying animation. If used after the demon had been killed, then the purification would yield nothing.