the hard way to solve is to take all possible permutations. The number of permutations = n! (factorial). So, for example, if the word has 5 letters there are 5! = 120 possible combinations. If the scrambled word was "odg" (three letters, which gives 3! = 6 permutations). You'd have the following:
first 1!-permutaion:
g (1! = 1) (working from right to left)
second 2!-permutations:
dg , gd (2!=2, "d" loops through both left & right positions of answer "g" from 1!).
third 3!-permutations:
odg, dog, dgo (loop "o" through dg from 2!)
ogd, god, gdo (loop "o" through gd from 2!)
thus we have (3! = 6 combinations).
Only "god" and "dog" make sense. Since the question asked for animals, dog is the correct answer.
For larger groups of words, try arranging them in alphabetical order then interspace consonents & vowels in alternating orders. Look for common letter combinations like 'ing' and 'er'. Keep the scramble-word question/hint in mind, because the mind tends to work in mysterious ways to match letters with hint.
The only sure-fire solution technique is to calculate all possible permutions using factorial (!), then the answer will be one of the resulting permutations ... just providing some general info here