Lampridius

Aelius Lampridius wrote biographies of several of the Roman emperors, one of which, that of Elagabalus, is dedicated to Constantine, suggesting that part of his life was passed under that emperor. Nothing more seems to be known of him.

Vita Commodi

ch. IX:

With his club he struck down not only the lions masquerading in woman's clothing and a lion's skin but even many men. Halt and lame men he dressed up as giants, so that covered with rags from the knees downards they crept along like serpents, and transfixed them with arrows. The shrines of Mithra he defiled with human blood, judgeing that in this way he would terrorise by deed as well as by word.