Conjure Monstrosities V.S

You utter foul words, taking 1d6 damage per spell level to summon two Monstrosities from a small portal from your blood. You choose the Monstrosities type, which must be two challenge rating 1/4 or lower, such as a Bone Whelk or a Young Kruthik. They only disappear when they drop to 0 hit points or when the spell ends.

The creatures obey all your commands without requiring actions as long as you hold concentration and the creatures don't disappear for 1d4 rounds when you lose it. the creatures run on your initiative directly after your turn. If not given commands or concentration is lost the creatures will attack indiscriminately.

At Higher Levels. When you cast this spell using a spell slot of a higher level the challenge rating increases,  at 2nd it increases to 1/2, to 1 at 3rd, and increases by 1 for each spell slot above 3rd.