Use (Grind Attack)
The spikes allows Dillon to use a Grind Attack. After striking a grock or mine chunk with a Rolling Attack, hold the stylus on the touch screen as Dillon makes contact to perform this attack. Grinding targets will yield the most items since more hits are applied than with Rolling Attacks or Claw Attacks. However, in battle they take longer to defeat a single grock.
There are 3 different Spikes, each stronger than the last: