Great lookin' alien. I see you have found better way to solve the problems with "hands", i have a bit less "advanced" one too. You might want to try Plate, Modified 1 x 1 with Clip Vertical or Plate, Modified 1 x 1 with Clip Horizontal for feets, as it looks quite good that way.Also this part:
Appendage Spiky / Bionicle Spine works great for spiked tail. This is just suggestion not demand or anything like that.