Double-stuff Oreo Cookies
Marachino cherries with stems
Chocolate chips
Butter
Slivered almonds (or strawberry hearts candy)
Hershey's Kisses
Red piping gel (or pink icing)
 

Refer to the images below:

Remove one side of the Oreo cookie for the base. Melt chocolate chips with a little butter and dip cherries in melted chocolate mixture. Place on cookie. Place a Hershey Kiss beside cherry (as shown), fixing with more melted chocolate. After the chocolate has set a bit, add ears with either almonds, or for a nut-free variation, two candies such as strawberry hearts hard candy.  Add two eyes and a nose with either piping gel or icing. Let harden and keep in an airtight container.

Enjoy your mice!