sed -i -E "s/еж([аиу][^а-я])/ёжик\1/g" *ru*
grep -E "еж[аиу][^а-я]" *ru*
Comment: [^а-я] includes all spaces and punctuation and also finish of string
<level-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:maxLevel="1" android:drawable="@drawable/hogcount1" />
<item android:maxLevel="2" android:drawable="@drawable/hogcount2" />
<item android:maxLevel="3" android:drawable="@drawable/hogcount3" />
<item android:maxLevel="4" android:drawable="@drawable/hogcount4" />
<item android:maxLevel="5" android:drawable="@drawable/hogcount5" />
<item android:maxLevel="6" android:drawable="@drawable/hogcount6" />
<item android:maxLevel="7" android:drawable="@drawable/hogcount7" />
<item android:maxLevel="8" android:drawable="@drawable/hogcount8" />
</level-list>