Thunder Arrow (サンダーアロー Sandā Arō?) is one of Knuckles the Echidna's special attacks in Sonic Adventure 2 and Sonic Adventure 2: Battle. When performing this technique, Knuckles strikes his opponent with bolts of lightning.
When performing the Thunder Arrow, Knuckles thrusts his right fist forward and shouts "Take this". He then forms several thin but straight lighting bolts above his opponents to attack them with. In gameplay, Thunder Arrow targets the opponent wherever they might be and causes damage when it hits.
Thunder Arrow is first performed by Knuckles during the boss battle against him in the Dark story. Here, Knuckles will begin using it after his health has been reduced to half, although the attack can be better avoided here.
Thunder Arrow can only be performed by the player by playing as Knuckles in the games' two-player mode. Additionally, Thunder Arrow will disorient the opponent for a short time by disturbing the opposing player's controls. To use it, the player must press // on the ground after collecting 40 Rings. To use it again, the player has to collect another 40 Rings. In two-player mode, Thunder Arrow is nearly impossible to avoid, unless the other player uses either Dig or Glide. If Knuckles wears his alternate suit, he can perform it with just twenty Rings.
In other media
In the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics, the Thunder Arrow has appeared several times. In this media, the Thunder Arrow is similar in appearance to the Chaos Spear, except the user summons them in bursts of energy instead of throwing them as spears.