Related Clues:

• Express team?
• Racehorses, informally
• Small horses
• Cheat sheets
• Deliverers of express mail?
• You can bet on them
• Small liquor glasses
• They're played at the track
• Shetlands, e.g.
• Shetlands et al.
• Some gamblers play them
• Racehorses
• Subjects of many bets
• Track animals, casually
• Track bettors play them