What is this creature I found on my house?
Well, your question ended up being closed... If I understand it correctly, you simply asked "what is this creature?" and, after that, you asked "what species is this?". That being the case, the question seems to be clear enough to me.

Therefore, let's see:

What is this creature?

It's a caterpillar of a moth from the Genus Orgyia.

What species is this?

The Wikipedia link above lists more than 40 species. Here is, for instance, Orgyia antiqua:



And Orgyia leucostigma:



But my guess is that your specimen is Orgyia australis (specially if you live here down under):



Adding your location will greatly improve the chances of defining the species inside that genus.

Conclusion

That's simply a caterpillar (larva) of a moth from the Genus Orgyia. Narrowing it down to the species depends on you adding more information to the question, specially geographic location.