My two-month-old domestic kitten suddenly got a small hard lump on its forehead, under the skin, that moves with the skin when pushed.

The lump on the forehead may be from bumping into something during play, causing a bruise under the skin; this usually goes down in a few days. If it lingers, give pet-specific anti-inflammatory medicine with external bruise-healing treatment.

If the lump keeps growing, it is more likely a subcutaneous lipoma, which may need surgical removal when large.