Step 1: Set the criterion. To qualify as a habit disorder, a behaviour must be repetitive, relatively automatic, and performed with little conscious control, often serving to discharge inner tension.
Step 2: Test each option. Nail biting and thumb sucking are repetitive tension-relieving habits, and tics are involuntary recurrent movements or vocalisations grouped under tic disorders. All three satisfy the criterion.
Step 3: Find the misfit. A temper tantrum is a reactive emotional explosion triggered by frustration; it is a behavioural reaction, not an automatic repetitive habit, so it does not belong to this category.
Step 4: Conclude. The one that is not a habit disorder is the temper tantrum.
\[\boxed{\text{Temper tantrum}}\]