Salty is a bit upset.

You see, the cats in the household don't really like his chosen costume and they have been making fun of him all week.  In fact, Mittens actually told him that he looked girlie and un-scary.  He even went so far as to tell Salty that he should just go as he is because that is scarier than any costume he could come up with.  Salty retaliate with a bit of his own wit by telling Mittens that the stupid 'cat mask' he chose is stupider than any of the other costumes and if anyone was un-scary it was him.  Mittens, enraged by that comment, told Salty....oh....it's sooo awful but.....okay-Mittens told Salty that he was-----acting human!