What this coin looks like (obverse, reverse, mint mark location, special features, etc.):
One major variety is the 1855 Braided Hair Large Cent (Penny) which had a blob or "knob" on the liberty's ear and only exists in the Slanted 5's variety. This "Knob On Ear" variety features an extremely obvious blob above the ear on the liberty portrait. This was the result of breaks and cracks in the die which resulted in an error on the coin. The knob on the ear is depicted above in the example image of the coin.
Coin valuation chart: Typical coin prices, values and worth per grade or condition - in USD