Rare Hybrid / Namjin

"Can I have this one ?"said Namjoon with a cheerful tone but the shopkeeper was a little bit nervous and he looked at the gigantic cat.
"He is a rare hybrid sir, you sure you want it ?"said the shopkeeper nervously and Namjoon just looked at him and then looked back.
"Why did you say that ? Did he do something bad in the past ?"said Namjoon tilted his head and the shopkeeper just gulped and said.
"He killed his previous owner,"

A lot of grammatical errors lmao