I found these definitions in the book  and in the paper :
Kratt: a demon who stole and brought food, money and other wordly goods to its maker and owner in the form of a whirlwind or meteor-like tail of fire
Pisuhänd: tail of fire, treasure-bringing goblin
Puuk: treasure-bringing goblin
Also, there's an additional passage:
Kratt, also called puuk, pisuhänd, tulihänd, hännamees
It's quite common for the same entities appear with different names and appearances in mythologies.
This happens, often, because there are different versions of the same tales that change over time or according to the regions. And someday, someone compiles the legends and discovers that there are characters that are, practically, the same entity and ends up merging them.
I was answering a question from the Inuit culture, that a creature had different names and appearances. The representation was like as a bear, a creature with the size of a finger and sometimes as an invisible being. Some sources, however, cite him as a sea monster, a huge white bear, or even that his body is covered with eyes .
I found variations of his name as: Tornarsuk, Tornaq and Tungrangayak.
Just for fun, while I was researching tales with those creatures, I found something very funny/interesting (here):
In Estonian mythology, a Kratt is a magical creature. Essentially, Kratt was a servant built from hay or old household items. Therefore, the Estonian government uses this character as a metaphor for AI [Artificial Intelligence] and its complexities.
 LEACH, Maria; FRIED, Jerome. Standard Dictionary of Folklore, Mythology, and Legend. Funk & Wagnalls, 1972.
 BECONYTė, Giedrė; EISMONTAITė, Agnė; ŝEMAITIENė, Jovita. Mythical creatures of Europe. Journal Of Maps, [s.l.], v. 10, n. 1, p. 53-60, 9 dez. 2013. Informa UK Limited. http://dx.doi.org/10.1080/17445647.2013.867544.
 COULTER, Charles Russell; TURNER, Patricia. Encyclopedia of Ancient Deities. Chicago: Routledge, 2013.