Possible Clues:

• Pet alone evolves as larger animal
• Gazelle, e.g
• "...where the deer and the ___ play"
• Savanna springer
• Bet a long leaping stride is natural to it
• One of the Springboks has unnatural pale tone
• Trained a lone pet for one of the Springboks
• Gazelle or impala
• Would the insect run away with this for one buck?
• Impala or kudu