A friend of mine in Canada knows people who work in Bioware. She said there was an easter egg he snuck into one of the games involving a space hamster (supposedly not the main one). I'm trying to find it, but in looking for it, I found this:
Citadel HamsterThat reminds me, I don't have the Citadel pack yet (gonna get it soon, but wanted to hold off on spending a lot of money. Also doing achievement,s which have earned me quite a few origin points, which will save me some money ^.^
She also said that he tried to sneak a wedding proposal easter egg into the game, but apparently they caught that one at some point, and told him he wasn't allowed to do that