I don't really know the counters of ziggs, yasuo was the one for me because of his windwall this is why you won't see all the champs on the threat list in my opinion it depends on the player not on the champ if he/she can counter Ziggs or not, this champs is effective against champs with low magic resist, meelee champs, but works well against a lux as well bucause of his range and knockback on W (all abilities has the size of 2 flashes) so if you are behind in farm and the enemy is feeded you can farm from a long range with Q and E but be careful don't waste your W because ziggs is slow! your only chance to escape is your W which knocks bac enemy and works as a flash for you.

Ziggs has great poke with his Q but it takes some practice to get used to it.

Many players don't know but you can cast your W on towers at 25%health this is around 700-900 hp and you can easily kill towers with your passive as well it has 11sec cooldown but towers and champs feel it when it hits ;)

Passive- great +dmg based on your AP can be used really affectively against structures, has a 11 sec cooldown.

Q- grreat poke, long range, farm from safety distance, amazing dmg, short cooldown.

W- instantly destroy towers below 25-35% health (around 700-1000 hp)

E- Slowing enemy, helps farming, doesn't do much dmg but enemies fear it so they keep distance hwen you use it.

R- Mega Inferno, don't need to say anything, it just KILLS EVERYTHING!

pros: see above

Cons: Ziggs is slow this is something you need to accept this is why I build Zhonya's and Luden's Echo.