This group was originally a gang of underworld Dueling criminals working under Madam Heartthrob and rivaled's own before they began to work together. All of them died tragically and were eventually reincarnated as Barians.
After failing to obtain the Legendary Numbers, Vector summoned the members of the Fiendish Finger to accompany Heartland's Fearsome Four in their journey to take the "Numbers" from Simon Notroson, , Farakad, , and .,
Being Barians, the Fiendish Fingers have superhuman abilities such as teleporting and taking into alternative forms that give them unique abilities, such as Mimizumi's tunnling capability and Hiru being capable of draing the life energy of others with just a touch. They have also shown the ability to alter a Duel by using a Crest akin to that of Don Thousand's Emblem to halve the opponent's Life Points and add it to their own at the very beginning of the Duel, effectively cheating.
Each member has an alternate form based on different invertebrates.
|Identity||Number Card||Current Status|
|Madam Heartthrob||Number 0.5: Kraking||Unknown|
|Mimizumi||Number 1.5: Earthquake Worm||Unknown|
|Kani||Number 2.5: Guillotine Crab||Unknown|
|Hotaru||Number 4.5: Blazing Firefly||Unknown|
|Bachin||Number 5.5: Parasoid Queen Bee||Unknown|
|Hiru||Number 6.5: Power Leech||Unknown|