Yakdoriga is a creature vaguely reminiscent of a frog, insect, and octopus all in one being. It possesses a long, red, flexible body with slimy, splotched skin. It has numerous tentacle-like arms, each long and ending in a series of spines and what appear to be suction cups. It doesn't seem to possess any teeth; rather, its mouth is wide and gaping, with thick lips, and its huge tongue is visble inside. The creature's eyes sit closely above its mouth, small yellow and frog-like in appearance. Out of the top of its head, two grasshopper-like antennae protrude. Yakdoriga is a very large creature - at least twice the size of an ordinary human being.
When Natsu Dragneel locates and infiltrates the Tartaros headquarters, Kyôka, in the middle of torturing Erza Scarlet for information on Jellal Fernandes, leaves to investigate the ruckus, calling forth Yakdoriga to watch the Fairy Tail Mage in her place. Descending from the roof into the prison, Yakdoriga moves to grab Erza with its tentacle-like arms, though quickly jumps back when Kyôka demands from it not to touch the redhead. Later, under Kyôka's orders, Yakdoriga electrocutes Erza, both starting and stopping on command. When Erza refuses to cooperate, Yakdoriga is ordered to electrocute Erza once more, something it obediently does.
Some time later, as Yakdoriga guards Erza, Lisanna and Natsu -imprisoned elsewhere in the Tartaros headquarters- manage to break free with the help of a heat sword. Finding Erza's cell, the two barge in and succeed in freeing Erza from her restraints. Now able to use her Magic, Erza Requips into her hakama clothes and attacks Yakdoriga, knocking it unconscious and gleefully wearing it over her shoulders in triumph when Kyôka comes to check on them.
Curse and AbilitiesElectric Charge: Yakdoriga has shown the ability to release electric-like waves from the ends of its tentacles, in a similar way that an electric eel produces static shocks from its skin, doing so once when it intended to torture Erza Scarlet. In addition, when it was reprimanded, the creature instantly ceased creating the currents.
Coalescence: Yakdoriga has demonstrated the ability to morph through walls to travel and appear in separate places, doing so to enter a Tartaros prison cell when called by slowly emerging and descending from the roof.