2) Common insult amoungst lazy, bone-idle slobs (usually males) who lack sufficient intellect and/or articulation to create a more competent insult
3) Used as an exuse by young human males when they misplace something during the education process.
2) "You are a kong-plinger sometimes, Steve!" (Anon - lazy bone-idle slob)
3) "The kong-plinger in the desk stole it, Sir!" (young human male)