This is
not an iridescent shark catfish aka IDS.
I'd guess indeed the MGC or a hybrid thereof based on the "thumb-like" head / cranial shield profile, as GFK101 puts it, thanks to him.
Have you looked and read my thread and the threads linked therein?
https://www.monsterfishkeepers.com/...giant-catfish-juvi.584508/page-3#post-8277686
If you provide more pics, especially dorsal view and mouth shape view, we could be more certain.