to be a copycat

someone who copies others

to be a barrel of laughs

someone who is really funny likes talking jokes

chatterbox

someone who talks non-stop

busybody

someone who has his/her nose in everyone else's business

what a rip off

example:I bought a watermelon for 5.000 dolars

to be a worrywart

Meaning:Someone who worries about everything

to be a couch potato

look at Jack!!He is a  couch potato.