Synonyms For "Rat" :

1 syllable:

bum, crumb, fink, git, grass, puke, scab, shit, shop, skunk, snitch, stag

2 syllables:

betray, blabber, blackleg, denounce, lowlife, rotter, scum bag, squealer, stinker, stinkpot, tell on

3 syllables:

betrayer, dirty dog, give away, informer, strikebreaker