Morpheus, of all his numerous train, express’d
The shape of man, and imitated best;
The walk, the words, the gesture could supply,
The habit mimick, and the mein bely;
Plays well, but all his action is confin’d,
Extending not beyond our human kind.
Another, birds, and beasts, and dragons apes,
And dreadful images, and monster shapes:
This demon, Icelos, in Heav’n’s high hall
The Gods have nam’d; but men Phobetor call.
A third is Phantasus, whose actions roul
On meaner thoughts, and things devoid of soul;
Earth, fruits, and flow’rs he represents in dreams,
And solid rocks unmov’d, and running streams.
These three to kings, and chiefs their scenes display,
The rest before th’ ignoble commons play. 
- Morpheus class | includes all human-like objects; most complex and autonomous
- Phobetor class | includes all animated objects having less complexity that Morpheus-class objects
- Phantasos class | includes all inanimate objects
Notes & References
1. Ovid, Metamorphoses.