I'd imagine whales as slang and whaling metaphors have existed for quite some time. There's the expression "a whale of a tale". I think for gaming it relates m

I'd imagine whales as slang and whaling metaphors have existed for quite some time. There's the expression "a whale of a tale". I think for gaming it relates more closely to fishing and whaling, and how fishing is perceived. You're not hunting fish, you're fishing. I know poker uses both fish and whales as slang. If you rely on a couple big customers or players then you're waiting for that one big catch most of the time. Whales weren't just caught for their edible meat, and the other products such as oil were likely more important in the past.