One of the miscellaneous secondary weapons is the teddy bear. Locate it after earning the Scorpion Sword in the clock (west) tower. There are three encounters with a giant golem enemy in the clocktower when you initially go through it; the first is before you start negotiating the vertical climbing of the tower (past); the second is atop the clock tower (past); the third is is stationary and throws exploding monsters in the clock tower's second area (past).
Look for the room where the second giant golem enemy is. You will need to be in the present (so find a time portal) and drop into the water-filled dead end past the golem's room. Break the wall and retrieve the teddy bear.
The teddy bear is almost unbreakable and does almost no damage, but has the ability to restore lost life to the Prince with each successful blow on an enemy.