At standard IQ tests? Surely the creature doing a a standard IQ test needs at the very least opposable thumbs?

There will of course be exceptions, but a brain damaged but somewhat functioning human will always score better than a non-human at human-designed intelligence tests.

The argument isn't that a dolphin or bonobo isn't potentially smarter than a brain damaged human, but that by designing our tests for human use we are explicitly excluding non humans.