Pepperoni slices, often

• Sculls in a quad scull, e.g
• A couple of quarters?
• One's pawns on a chessboard, e.g.
• Oars in a quad scull, e.g
• The planets, without Pluto
• Santa's reindeer, traditionally
• Set of eight
• Crew, not counting the cox, perhaps
• Four pairs of volunteers beset by obsessive behaviour

Wiktionary Word definitions in Wiktionary
n. A group of eight things