There are a lot of pharaohs and gods with weird beards running around ancient Egypt. How will you know which one is Osiris? Keep an eye out for the good-looking guy with green or black skin.
Build: Physically fit, but dead
Complexion: Some say dark, some say fair. In paintings and sculptures, he often has green or black skin.
Hair Color: Unknown (always hidden under a wig and/or crown)
Facial Hair: A very sexy pharaoh's beard
Scars/marks/tattoos: Scars where Seth once cut him into 14 pieces
Jewelry and accessories: Royal necklaces and a crown with tall plumes; two special scepters (called a crook and a flail) as marks of his pharaonic office
Clothing: White royal robes, white mummy wrappings, and sometimes both
Armor: None except his mummy wrappings.
Type of Weapon: Osiris has people for that.
The Four Sons of Horus
The Duat (the afterlife/land of the hidden sun)
The Hall of Two Truths (the hall of judgment in the afterlife)