dnd 5e – Can you summon a flail snail or an invisible stalker with Elemental Conjure?

Choose an area of ​​air, earth, fire or water that fills 10 feet
Cube. An elementary challenge rating of 5 or lower appears in a
Unoccupied space within 10 feet of it. The elementary disappears when
drops to 0 hit points or when the spell ends.

Can it not be convened unless it belongs to four elements? For example, can I invoke a snail flail or an invisible stalker with Elemental Conjure?