Does Ralph Wiggum dream of being a Viking or is it a metaphor?

[MarvinTheParanoidAndroid]

When Ralph says he's a Viking, does he mean it literally, as in he dreams of being a Viking, or is it metaphorical, meaning he's just really skilled at sleeping? Does he dream of being a Viking every time he sleeps? How could you be so skilled at sleeping? Is there any evidence that he's always a Viking in his dreams, is there any evidence he's a sound sleeper? He appears to sleep on demand and on a whim, so could it be the latter?

 

[Wuornos]

I don't know, but men should be culled regardless.

 

[Stephanie Bustcakes]

It's because when he sleeps he raids villages, stealing their valuables and kidnapping the villagers to sell into slavery, then performs human sacrifices to his pagan gods.