> Citation needed.
I think that this is probably a dangerous game to get into; calling for citations is, I think, only likely to be helpful when there is a mutually recognised authority to cite (and, besides, when the claim to be resolved is a factual one—'biased' is not a characterisation that can be proven or disproven without some really careful definitions, on which two disputing parties are likely to disagree). Here's the first hit in a search for "Snopes biased". I've intentionally mangled the first component of the URL to avoid linking to whatever kind of site this is.
http://d@ilyc@ller.com/2016/06/17/fact-checking-snopes-websi...
I don't know Daily Caller, but the title alone makes me fairly confident that it's a biased source; but there it is, a citation to back up the claim that Snopes is biased.