Does Vorpal Spikes proc Rylai's crystal scepter slow?

Solution 1:

I'm thinking it does add the slow from Rylai's. I've been looking on the wiki's and I found this:

The following will not trigger a slow:

• Champion abilities that do not trigger spell vamp
• On-hit damage damage dealt by items
• Summoner Spells, such as Ignite and Smite.
• Damage dealt by the auto-attacks of Clones and Pets/Minions.

http://leagueoflegends.wikia.com/wiki/Rylai's_Crystal_Scepter

Then on this page http://leagueoflegends.wikia.com/wiki/On-hit_effect#Items I found under:

Abilities — do apply spell vamp:

Area Of Effect
The following effects deal area of effect damage, but are not classified as splash damage: Cho'Gath's Vorpal Spikes