Idiom - Someone who is an important & influential person (particularly in a business)
the big cheese
Idiom - one bad person who negatively influences a group of people
rotten/bad apple
Idiom - an unpredictable person who is likely to cause damage if not kept under control
a loose cannon
Idiom - a lazy person, someone who lives a sedentary lifestyle
a couch potato
Idiom - a negative person who ruins other people´s good times
a wet blanket
Idiom - someone who is mentally or physically strong and copes with difficult situations
a tough cookie
