What level would a Speak with Monstrosities spell be?

[Unoriginal]

Let's say someone in the campaign setting was attempting to create a Speak with Monstrosities spell, to communicate with creatures like Ettercaps or Phase Spiders which are unaffected by both Speak with Animals and Tongues.

At what level would you put such a spell?

Personally I'd put it at lvl 3, but maybe lvl 2 would be fairer?

[Chronos]

Monstrosities are more exotic than animals, but not all that much more so. Call it one level higher than Speak with Animals.

[Amnestic]

2nd or 3rd sounds about right. 3rd has Speak with Dead and Speak with Plants for comparison.

I think for Rangers sake I might put it at 2nd instead of 3rd.

[Protolisk]

2nd level. Speak with Animals is "easy" because beasts tend to have their own forms of communication similar to humanoids like noise and body language while Speak with Plants allow you to speak with things that generally have no concept of communication beyond chemical signaling. Speak with Dead allows you to talk to something that literally has no form of communication, its dead.

Speaking to an Owl Bear, a Displacer Beast, or similar, shouldn't be all that much harder than a normal beast.

And there is a perfect spot between the "easy" Animals at 1st level and "nearly impossible" Plants and Dead at 3rd level.

[Zhorn]

communicate with creatures like Ettercaps or Phase Spiders which are unaffected by both Speak with Animals and Tongues.
True on Speak with Animals, but Tongues does work on them, to a limited extent.
Neither Ettercaps or Phase Spiders have a language in their stat blocks, so if you cast Tongues on yourself they don't have a language to comprehend what you are saying in.

BUT, the target of the spell needn't have a language to be able to comprehend the languages of others, the target just has to be a creature.
Cast Tongues on the Ettercap or Phase Spider instead of on yourself and they will be able to understand anything said to them.

HOWEVER, not having a language to speak of their own, the communication would be one way, as they would be unable to say anything in response.
Being said, creatures like that would be unlikely to care and opt to continue their attempt to eat your face.

Another fun one to use (and safer than a touch spell) is Sending, as the target only needs an Intelligence score of at least 1, and does not require a shared language to understand the meaning of what you tell them.
What would be up to debate and subject to DM fiat on this one is the ability to respond. If you rule that the Sending is entirely telepathic, then the receiving creature needn't have to be able to speak to respond in kind. If your table rules that Sending is spoken aloud, then it is also a one way communication.

As for the thread's primary question, I'd go with 2nd level. It's not a universal translator like Sending or Tongues, nor is it crossing the 'is this even a creature?' line of Speak with Dead and Speak with Plants, all of which are 3rd level.
Speak with Monstrosities at 2nd level sounds fair.

[Satori01]

A Speak with Monstrosities spell would be fine as a 1st level spell.
Just because monstrosities tend to be more powerful then beasts does not necessarily mean a spell meant to communicate with monstrosities is automatically of higher level.

A SwM spell is a very limited spell application, that may be of questionable utility.

Even if you can talk to Displacer Beasts, doesn't mean that the creatures will say anything beyond "Yum. You look tasty".

Low INT, and sour dispositions make most Monstrosities poor conversationalists, I imagine.

[Protolisk]

A Speak with Monstrosities spell would be fine as a 1st level spell.
Just because monstrosities tend to be more powerful then beasts does not necessarily mean a spell meant to communicate with monstrosities is automatically of higher level.

A SwM spell is a very limited spell application, that may be of questionable utility.

Even if you can talk to Displacer Beasts, doesn't mean that the creatures will say anything beyond "Yum. You look tasty".

Low INT, and sour dispositions make most Monstrosities poor conversationalists, I imagine.

Well, it also covers the odd edge cases of Centaur and other intelligent monstrosities. If your party has no elvish or sylvan languages, it still helps. Behirs with draconic. Minotaur with abyssal. And then there are the ones like Umber Hulks, which have language, but good luck learning the innate Umber Hulk language. In general, there are a lot of languages that this spell sort of mimics, but still aren't Tongues level of actually being those languages, so once you go from Speaking with Minotaurs, looking at its demonic buddy that only speaks Abyssal would still be a no go with the spell.

Though I think its because of these intelligent creatures that have language is probably why Speak with Monstrosity doesn't exist.