Which is correct: "spottier" or "more spotty"?
For example: The poison dart frog was _________ than the glass frog.
Which is correct: "spottier" or "more spotty"?
For example: The poison dart frog was _________ than the glass frog.
Two-syllable adjectives ending in -y take their comparative and superlative in "-ier" and "-iest". (Practical English Usage, Michael Swan)
Although this rule has not been perfectly adhered to in the past, there has been an unabated trend towards conformity of usage. This can be seen in the following ngrams.
The choice is therefore yours, but taking into account the trend shown by the ngrams (it spans more than a century), you might consider that you are making a contribution to the language by choosing "spottier".