Strykewyrms occasionally dig underground and attempt to attack you from beneath, hitting between 500 and 2,000 if you don't move out of the way. To avoid this attack, simply step one space back from where you are standing.
You can only kill Strykewyrms when assigned a Slayer task, otherwise attempting to investigate the mounds will do nothing. Although they are found in a desert area, Waterskins are not needed when fighting them.
The chance of receiving better drops is increased by the Ring of wealth, Luck potion, Collector's insignia, Leprechaun hat or Luck of the dwarves.