Watching this excellent episode the other day it occured to me that Evilseed might be symbolizing marijuana.
Funny that a hooded man sells some bad seeds. When we see him talking to Skeletor on Skeletor's big screen me and my cousin laughed and pointed out that is looked like a drug dealer.
Not to mention it's "weeds" that grow and overtake everything.
I think they may have been secretly pointing out the evils of pot with Evilseed.