Abu Hurairah (May Allah be pleased with him) said:
The Messenger of Allah ﷺ said, "He who kills a chameleon at the first blow, such and such number of good deeds will be awarded to him; whoever kills it at the second blow, such and such number of merits will be recorded for him. And if he kills it at the third blow, he will get such and such merits."

Another narration is: The Messenger of Allah ﷺ said, "If anyone kills a chameleon with the first blow, a hundred good deeds will be recorded for him; less than that will be recorded for him if he kills it at the second blow, and still less rewards will be recorded for him if he kills it at the third blow."

[Muslim].

وعن أبي هريرة رضي الله عنه قال: قال رسول الله ﷺ : “من قتل وزغة في أول ضربة فله كذا وكذا حسنة،ومن قتلها في الضربة الثانية، فله كذا وكذا حسنة، ودون الأول وإن قتلها في الضربة الثالثة، فله كذا وكذا حسنة” ((رواه مسلم)). وفي رواية: "من قتل وزغاً في أول ضربة، كتب له مائة حسنة، وفى الثانية دون ذلك، وفى الثالثة دون ذلك" ((رواه مسلم)).