Damaged nickel. Other coin should be posted in the ancient coin forum, but it appears to be a cast replica. Not sure what it's a replica of though, since ancient coins are far from my area of expertise.
My best finds:
1996 DDO-001/FS-101: http://goccf.com/t/372066
1995 DDO-001/FS-101: http://goccf.com/t/376071#3225244
1972-P DDO-008/FS-108: http://goccf.com/t/405558
2000-D Maryland Quarter Rotated Die http://goccf.com/t/394553
1988-P "Reverse of '89": http://goccf.com/t/399390
Massive strike through error on 1957-P Jefferson nickel http://goccf.com/t/402781