One sentence. Correction please.

I was taking a walk and then I saw a squirrel pass by a shallow pond in which lots of minnow live with a chestnut on his mouth.

Does it sound all-fine? If necessary, your correction please. Thanks a bunch.

When I was taking a walk, I saw a squirrel with a chestnut in its mouth,  scurry by the shallow pond that contains lot of minnows.

A squirrel doesn't "pass by"

In case you understand Korean.
(Original text: 산책을 하던 도중 다람쥐 한 마리가 밤을 입에 문채 잔챙이들이 많이 살고 있는 얕은 연못 옆을 지나가는 것을 보았다.)

One sentence. Correction please. I was taking a walk and then I saw a squirrel pass by a shallow pond. The pond was filled with a lot of minnow.  The squirrel had a chestnut in it's mouth. 

Does it sound all-fine? If necessary, your correction please. Thanks a bunch.



In case you understand Korean.
(Original text: 산책을 하던 도중 다람쥐 한 마리가 밤을 입에 문채 잔챙이들이 많이 살고 있는 얕은 연못 옆을 지나가는 것을 보았다.)

I agree with Leigh Mumford and Richard S. but I do not think there needs to be a comma after <em>mouth:</em>

<em>When I was taking a walk, I saw a squirrel with a chestnut in its mouth scurry by the shallow pond that contains lots of minnows.</em>

Richard S. made very valid points about the usage of "scurry" and the syntax required for the English language.

I would probably revise it this way:

While taking a walk, I saw a squirrel with a chestnut in his mouth scurry past a shallow pond full of minnow[s].

I prefer "While taking a walk" because it is more concise and "While I was taking a walk" sounds a bit passive to me.  For more information about active versus passive voice:

https://owl.english.purdue.edu/owl/owlprint/539/

"The shallow pond that contains lots of minnows" implies that there is only one pond like that, so if you were referring to a specific pond that would make sense.  However, if it's just a pond that happens to be home to a lot of minnow you can use "a" — something you already know.

Minnow can be pluralized as either minnows or minnow.

How cute~  Did you really see that?  ^^