Question

i fixed it as you said, what do you think about my tercet now?

The Wild Dog

I saw a dog
Who walked in the fog
He couldn’t see and got stuck in a log.

He jumps up high
And pretends he can fly
Like a super hero in the sky.

He’s really really fat
He sits on a mat
All day, chewing on a hat.

Answer 1

I think your 3rd line is still too long to fit with the rhythm of the rest of the lines. Other than that, it is definitely better than your earlier draft.