Coins that were stamped twice, once properly and once "off center" are called "double struck".
Here is an example of such an error where the coin involved is a 19th century silver dollar, known as a Morgan Dollar. Also shown is an 19th century 8 Reales coin of Mexico.

Double Struck American Dollar and Double Struck Mexican 8 Reales
Here from the archive are further Double Struck Eight Real examples.

Other type coins from the archive are Half Cents, Large Cents and so forth:

Half Cent
Here, from the archive, are further Half Cent examples.

Large Cents

Here, from the archive, are further Large Cent examples.

Flying Eagle Cent (Flip double strike)

A close up of this double strike shows the word "America" along the dge:

Two Cent Piece Buffalo Nickel
Shield Nickel - - - Liberty Nickel
3 cent in Nickel Mercury Dime
Liberty Seated Dime - - - Barber Dime

Liberty Seated Quarter

Liberty Walking Half Dollar Franklin Half Dollar

See other Double Struck Walking Liberty and Franklin Halves

Eisenhower Dollar

Sacagawea Dollar Susan B Anthony Dollar