How many characters does the biggest word on this list contain?'Ostracods', which consists of 9 characters.
What's the highest possible score you could get in Scrabble using this list of words with 'o' as the first letter that end with 'ods'?As there are only possible, you're only viable choice is 'oxbloods' scoring 18 points.
How many possible words can you make using the combination requested?4 words!