From the page:
gusrillaUSean Newell1L
Looks like the old mascot. Slugerrrrrrrrr(rrrrrrr) has been revamped in the last few years and in this pic he's wearing an outdated jersey. Most likely someone got a hold of the old costume. Although, this whole thing does make being a Royals fan more enjoyable for me. Today 7:21pm
FreezyUgusrilla1L
Yep. The Royals and Slugger haven't worn that style of uniform (with blue sleeves) since 2005. Today 7:47pm
Those claims would seem to have merit.
http://kansascity.royals.mlb.com/kc/...errr_about.jsp