Possible Clues:

• That's all you have to do (poisonously) to make E Gaelic
• Snakes are totters
• Sounds as if they might give you some answer that could be fatal
• Mathematical reptiles
• They sound as if they could do some work, but not on foot
• What's so sad about the red is that there's not even one foot of them
• The snakes of summers, perhaps
• Summer biters?
• These creeps seem as if they would not make a 13 across
• Fifty such might have rung and have bitten