Shasa Tiel is the female Ishi Tib seen approaching Luke during his negotiations with Jabba the Hutt for the release of Captain Solo. She is clearly visible on screen over Luke's left (our right) shoulder.
Why?
First, it's a well established fact that the first act of Return of the Jedi is the greatest first act in cinema history. If you argue that point, you might as well go buy an "I'm stupid" pennant and attach it to a whip flag secured to your belt so that all bystanders can avoid your cone of ignorance. Any figure from the Jabba's Palace or Sarlacc Pit scenes is automatically a compelling candidate.
Second, from that iconic scene above, Shasa Tiel is the only character for whom we don't have an action figure (or viable stand in). Luke is encircled by some Gamorrean Guards, Tessek, Beedo (the VTSC Greedo is a stand in), Shasa Tiel, and Wooof. Completing scenes is one of the most satisfying things about collecting the 3.75" scale, and a Shasa Tiel figure would do just that.
Why HasLab?
Even though the Ishi Tib are a compelling alien species to us hardcore collectors, the average consumer probably has no idea that species even exists in Star Wars. Added to that, there is no vintage Kenner counterpart for casual collector nostalgia appeal. This would be a risky proposition for Hasbro to manufacture on spec, so let us fund it.