Swarm: When it has 1/3rd or less max HP, its Bug-type moves have 1.5x power.
Hidden
Sniper: Critical hits deal 2.25x damage instead of 1.5x.
Entry
The web it spins can be considered its second nervous system. It is said that a Spinarak determines its prey by the tiny vibrations it feels through the web.
PokémonPoké.
167
ProfessorProf.
Oak
Entry
Spinarak's abdomen mimics a larger predator to fool potential attackers. This method has proven very effective, since even regular hunters of Spinarak are mostly warded off by its intimidating appearance.