She is quite mild-mannered and kind, but has a mischievous streak.

Not that this slightly mischievous streak was without value.

Spirit is a courageous leader, but has a serious mischievous streak and great curiosity.

She is an intelligent girl, with a mischievous streak, but she also has a kind heart.

He has a mischievous streak, and ultimately, he lacks a conscience.

Whatever the reason, Ms. Lemper's mischievous streak has served her art well.

This somber young artist would seem to have a mischievous streak.

Myeloski, for all the seriousness of the situation, had a mischievous streak that was always present.

Western Scrub Jays have a mischievous streak, and they're not above outright theft.

Call it a mischievous streak, but I just couldn't let it stand at that.