The white, noble horse symbolises on the one hand positive strength. On the other hand it is worth in many (northern) regions of Europe as the legendary mythical creature which carries the souls of the deads ‘about the shore, by the river and in the other world’. It depends on the dream history.
Like the unicorn a mould stands for the striving for cleanness and innocence. In addition comes according to dream a feeling of the ejected being and the isolation.
Dream interpretation and meaning : Mould