Spinarak's Weaknesses

Best Counters

The types that are strong against Spinarak are Fire, Flying, Rock type Pokemon.

For the best defense, Rock, Steel, Ghost types have very effective defense against Spinarak, and will be resistant to damage from Spinarak's STAB attacks:

Psychic types will also deal super-effective damage against Spinarak, but be careful using Pokemon of this type because they may also receive extra damage from some of Spinarak's attacks!

Weaknesses

Spinarak's type is Bug and Poison.

Spinarak has a weakness to Fire, Flying, Psychic, Rock types. These Pokemon types will be strong against Spinarak, causing Spinarak to take a super effective double (2x) damage from attacks of those types.

Please keep in mind that Spinarak is resistant to attacks from Fairy, Poison, Fighting, Grass types, and these attacks are not very effective and cause reduced damage, so they should be avoided.