As I said, I could not find the text on the Hutts, it may be something I saw some one else say/post on these forums.

As for the "GM Interpretation? Yes I mentioned that as well already, but for me "They are completely immune to any manipulations via the Force" is fairly clear for me.

With the Hutts, WEG writers "assumed" that because Jabba wasn't affected by Luke's mind trick attempt, that meant that Hutts in general were immune/resistant to such things. And since WEG established a lot of the early Expanded Universe, other folks went with "Hutts are really hard/immune to Jedi mind tricks."

WotC did much the same with Toydarians based on Watto's line about how only money worked on him, which was probably more of an exaggeration/boast given Watto had no real idea he was dealing with a Jedi Master, and mechanically giving the species a bonus to resist the mind trick power.

Toydarians also have 2 ranks of "Nobody's Fool" to represent their resistance to forms of manipulation. That's more "face skill" than "force power" but it's what they get.

Toydarians also have 2 ranks of "Nobody's Fool" to represent their resistance to forms of manipulation. That's more "face skill" than "force power" but it's what they get.

They do? According to my book they "only" get Silhouette 0 and hovering as the species abilities.

Toydarians also have 2 ranks of "Nobody's Fool" to represent their resistance to forms of manipulation. That's more "face skill" than "force power" but it's what they get.

Where do you see this?

Might be that Mornmist is referring to an NPC stat block rather than the species stats listed in Enter the Unknown.

In SWTOR, several of the PC class stories show them as simply too strong-willed to have their minds manipulated by a Force user.

(The Bounty Hunter faces off with a Jedi at one point, and "You will put down your gun and surrender peacefully" while waving his hand, can be responded to with "You will realize what an idiot you look like" while also waving the hand. )