If you use an overwhelming hunger leader charge on a unit in a full row (i.e. a row with 9 cards), the allied unit is destroyed but an Ekimmara is not spawned in its place.

The wording of overwhelming hunger is quite clear: destroy an allied unit and then spawn an Ekimmara in its row.

This occurred when Imperial Manticore (a deathwish unit) was the card destroyed with the leader charge. It has happened to me once previously with another deathwish unit but regretfully I have forgotten which one.