Two can play this game (#3 (www.merriam-webster.com)), although it's obviously besides the point: which is to say, I think your disapproval and dismissal (better (en.wiktionary.org) words? (en.wiktionary.org)) of this collaboration as a gag is premature, as both entities are established and accomplished artists.
I understand my tastes do not mix with children in general, I was rather saying that although it sounds silly, the music on Crack the Skye is incredible. So more of a defense of Mastodon more than anything else.
Of course, it may turn out like the Aqua Teen Hunger Force COLON Movie (www.youtube.com), but I doubt it (since that is Adult Swim). Even if it did, I would obviously love it still ;)