HHN Bear was the first to do it well, and it struck a chord. At the risk of swelling some fellow OU members' heads, it helped that they did it brilliantly (e.g. only following "bear" accounts at first).
Again, YMMV, but for me, another giant creature so soon after just felt like trying too hard to capture that vibe again. Guide mentioned on tour that they try to only use a Pepper's Ghost every few years, to preserve the uniqueness of the effect. I think the same should apply to giant animals.