The term 'dingobrain' describes someone who is a complete idiot and is often used when someone has just done something stupid. The term describes how they have the brain of a dingo. The term was adapted from the famous shock jock Bob Francis who is on air in 5AA in Adelaide, Australia on weeknights. He often used the term 'dickbrain' on callers who he disagrees with, thought recently he has been using the term 'douche', interchangeably with dickbrain. Another similar terms that have been adapted is 'dingodick', which can be used instead of dickhead.
Although the term is already quite versatile, it can be added with other terms for more effect, this is done in the example, with another great term.
That kid is the biggest dingobrain twithead