Gotal's Tier 4 Smuggler Promotion Item (required for promotion to Tier 5) just got changed to the Thermal Shield. What's confusing is that the Thermal Shield description says that it's a Credit Item, not a Promotion Item, so I deleted it the first time that I got it. Make sure you don't make the same mistake! (BTW, you can view Gotal's levels on this post.)
UPDATE 6/6/14: As Luke the Skywalker pointed out in the comments, the Thermal Shield's description was updated to not only say that it's a Promotion Item instead of a Credit Item, but it also replaced the Holochess for Zuckuss.
Thermal Shield is a Tier 4 Promotion Item, not a Credit Item
The new Thermal Shield can be found easily in the 6-Energy Tier 4 Promotion Smuggler Saturday special missions. Here are screenshots of the rewards from 5 consecutive missions, 3 of which yielded the Thermal Shield:
Gotal is one of my favorite characters to use in missions because his Thermite Grenade attacks 3 adjacent opponents at once, and if he's strong enough, then in most missions, he can kill the opponents on the first try. The problem was that one of his Promotion Items to get to Tier 5 was the elusive Holochess, which used to be available only in Hero or Arena Crates:
Looks like that's changed now, and hopefully will remain that way. Enjoy the game and thanks for reading!