Blackwhip

Black Whip is a Quirk used by a previous user of One For All and was passed on to Izuku Midoriya.

Description
Its original user describes Black Whip as a top grade Quirk.

Black Whip allows the user to generate black tendrils from their arm and command them at will. It appears to be useful for capturing enemies and increasing one's own mobility by grappling to objects.

By the time Izuku acquires this ability, Black Whip has evolved within the core of One For All. When Izuku focuses on capturing a target and gets angry, this power explodes out of his arm. The black tendrils are much larger and powerful enough to cause Izuku great pain and force him into submission. The tendrils easily whipped Izuku around Ground Gamma and destroyed a number of its structures.

Later when Izuku used the Quirk again to grab onto some pipes that were going to hit him he found he could only use the Quirk for a brief amount of time because of how powerful it had become due to One For All. He was left with a numbing pain after using it.