I’m stuck on the back leg after the 10th and 12 th row to the end of the leg.

You’re going to continue in the 6 row stripe pattern in stockinette with decreases every so many rows.
Start with 8 rows in stripe and then work the decrease row. The pattern continues with stockinette rows ( knit a row, purl a row) until another decrease row.
What is the name of the pattern?

It is Pure wool entwine unicorn toy.

Do I have to work 6 even rows through out?

I’m still a little confused on how to do it.

Think of the 6 row stripe pattern as your background color. Follow the directions for decreasibg and rows between decs and at the same time repeat the stripe pattern. The photo with the pattern may help here.