That wouldn't be illogical either. Logic is about internal consistency. So consider logical self-identity: A = A, or otherwise, something, if it exists, exists as what it is (itself). Then excluded middle: A or ¬A (that's not-A), or something that exists either is what it is, or it must be something else. Then non-contradiction: ¬(A and ¬A), or something can't both exist as what it is and what it is not at the same time and in the same respect.
An apple is an apple, and something is either an apple or not an apple, and something can't be both an apple and not an apple at the same time and in the same respect.
What you're talking about is just something unknown: some kind of life that we're not familiar with. But we don't have to know what it is to know that it must be logically coherent (it is whatever it is, it is not whatever it's not, and it's not both what it is and what it's not at the same time and in the same respect).