Abraxan Feather

Wands with Abraxan hair or feathers as their core tend to be hard to control, but they are capable of performing strong spells when used by a master wizard. They are also considered to have a perfect balance in the strength and speed of spells that the wand can produce.

Acromantula Web 

Great Britain outlawed the implementation of Acromantula wands in 1782, stating that they were more effective for wizards or witches with sinister intentions. Those who used these wands typically followed a career as a criminal or illicit trader. They are adept at casting curses and practising the dark arts.

(URI) Note from “Silent Iron” (Your “Specialty” Trade Expert)

Even though Acromantula Webs are outlawed, some underground Wandmakers still make Acromantula Cores. You just need to which Corner Nook to look in. 

African Mermaid Hair

Wands made of African mermaid hair possess a distinct magical ability--if someone other than its rightful owner tries to pick it up, they will experience an electrical shock. Besides its defensive capabilities, it offers its wielder an increased lung capacity underwater (up to eight hours) and a proficiency in water-based magic.

Ashwinder Egg 

Ashwinder eggs exhibit extreme warmth before they hatch, and most of them hatch immediately after they are laid - Which makes it difficult to find a Core-Worthy egg. These eggs are highly valuable when used as wand cores, but the intricate process of converting them into magical cores makes them rather costly. Despite the difficulties, the outcome proves to be exceptional, as Ashwinder Egg cores offer great flexibility for numerous spells of the Conjuration school, which are particularly beneficial for Transfiguration-inclined wizards.

Augurey Tail Feather 

Although it was once thought that wands with Augurey Feather cores were associated with evil witches or wizards, in actuality, they do not have strong capabilities in dark magic and are not drawn to individuals with sinister tendencies. People possessing these wands are often misconceptions. Wands featuring an Augurey Tail Feather are adept at incantations from the Charms and Divination schools, creating a solid balance of capabilities.

Banshee Hair

Obtaining a wand core made of Banshee Hair is exceedingly challenging because the Banshee's lethal scream impedes the collection process. Wands featuring this ingredient lack the capacity to perform healing magic. However, a wand with Banshee Hair as its core makes for an exceptional duelling wand, providing a highly potent attack option.

*Basilisk Fang

Basilisk Fangs are excessively hazardous to handle, which makes them exceedingly challenging to apply in wand crafting. Moreover, the scarcity of Basilisk causes these elements to become even rarer. Wands with Basilisk Fang cores are in demand among dark wizardry practitioners. Basilisk Fang wands are particularly favoured by Slytherin pureblood families and are a highly-priced commodity, usually being a Heirloom wand. Basilisk scales strongly respond to Parselmouths, while these wands excel at castings of curses and other forms of dark magic.

*Basilisk Scale

The toxicity of the Basilisk Fang is well-recognized, but its scales are equally valuable. When these scales are applied as a wand core ingredient, they provide a pleasant finishing touch to various incantations. To no surprise, these wands favour hexes and curses. This ingredient is highly desired by dark wizards, resulting in the scarce availability of Basilisk Scale wands on the market. Given the affluence of many Slytherin pureblood families, a Basilisk Scale wand would serve as a luxurious addition to their repertoire, provided they have the financial means to obtain one. Basilisk scales are particularly receptive towards the Parselmouth language, as they react more intensively to the whispers of those who speak it.

*Basilisk Skin

Wands featuring Basilisk Skin as their cores are exceedingly rare, as the creatures themselves are rare and challenging to vanquish. Heirloom wands with this material are handed down through families and tend to bond with a Parselmouth or a young witch/wizard who aspires to pursue dark wizardry. Unfortunately, individuals wielding wands with Basilisk Skin as their cores are generally prone to negative outcomes, as they harbour malevolent intentions or actions.

Basilisk Venom 

The Basilisk Venom is not primarily used as a wand core ingredient; rather, it serves as a secondary element, meaning it can complement the primary core material without any mishaps or malfunctions. When blended with another Basilisk Core or Dark Core element, the Basilisk Venom provides these effects: enhanced proficiency in Dark Magic, improved lethality, and heightened control over a Basilisk, although the latter feature is only accessible to individuals who speak Parselmouth.

Billywig Shell

Billywig beetles' shells, which are made of aramid-like compounds, are highly valued as wand cores because of the magical properties that are unleashed when they are crushed in a mortar. Billywig cores allow spells to be cast quickly and effortlessly. These cores are popular among Ravenclaw students for their quickness, lightweightness, and ease of use.

Billywig Stinger

Billywig Stinger wands tend to form a connection with lighthearted pranksters. These wands are known for their tendency to change their mood or behaviour unexpectedly. They are proficient in the strongest Charms, but their sporadic mood swings may cause them to refuse to cast spells or become unusable altogether.

Boggart Skin

Boggart skin wands are strongly associated with the Dark Arts, and their proficiency in Transfiguration is unmatched. Additionally, their skill in Divination and Legilimency is remarkable, given that a boggart takes the form of the viewer's greatest fears. If a boggart is killed, making a wand from its skin is an intensely traumatic event, resulting in its creation being more likely as a wand for a Slytherin and highly unlikely to be a wand for a Hufflepuff.

Boomslang Venom

The creation of wands with a core of boomslang venom is extremely perilous, and whether or not it is worth the risk to work with the venom is widely debated. The venom can be crystallized or used in its liquid form, and these wands give their wielders a slight increase when casting hexes and curses. In most instances, the venom will be crystallized for safety reasons, but those who use the liquid form and succeed in making a wand will have a very powerful wand for Transfiguration, which is highly valued among witches and wizards from the Slytherin House.

Bowtruckle Bark

Although Bowtruckle Bark doesn't make for a robust wand core, it strengthens nature-oriented spells. Rowans, the tree that Bowtruckles commonly guard, form the best match for a wand with this core.