> Is a shapeless creature even logically coherent?

Do you see how your argument is self-defeating?

According to logic that humans have developed, there is such thing as a "shape". But Western philosophers have pondered the innateness of a "shape" or an "object" from very early on (Plato, through Leibniz, beyond).

"Shape" and "logic" are both human constructs articulating "structure", another human construct.

A shapeless creature doesn't need to be "logically coherent" to exhibit intelligence; logic, truth, and structure are features that have emerged from human intelligence. I wouldn't accept the argument that an entity must exhibit the same features to qualify as intelligent simply because humans have.