Memoryhead is one of the most fascinating mysterious Gaster-related things for me...it’s hard to speculate on them much (other than what i’ve gone over already regarding their connection to Gaster) cause they’re so enigmatic but that wont stop me from trying
one interesting thing about Memoryhead is how they refer to themselves as “us” whereas the other amalgamates use singular forms (I/me/my). despite being composed of many different monsters fused together, the others seem to retain a sense of individuality while MH does not.
this is especially interesting to me cause i’m not sure that Memoryhead is actually a proper amalgamate. i know they are listed as Amalgamates but i don’t know if they have constituent parts aside from Gaster? maybe they do - like i said, they’re very mysterious so i can’t say for sure what’s going on there. it’s possible pieces of different monsters merged together to make them.
however if they are simply pieces of Gaster like i assume, it’s odd how they’ve split off into a trio, look like they have multiple faces on their ‘bodies,’ and as i said above, speak of themselves in plural form. a couple of the faces even resemble Sans and Papyrus a little too
perhaps it’s reflective of Gaster’s fractured state of mind as Memoryhead. he’s lost his sense of self. i also wonder if MH is trying to recreate something from its past? they call on you to join the fun, say it’s a real get together...what if they tried to form something like a happy little family, based on their former self’s memories?
during True Pacifist’s credits, it says the Amalgamates are living together with their families. i love the idea of them going with the skelebros but i kinda wonder if Alphys, Sans, or anyone (except Frisk) even knows about their existence. maybe the family MH is with is its own self?
another neat detail is how it looks like Memoryhead has a phone + cord held up to their head. maybe something else that was taken from Gaster’s memories. or it could just be because the path to sparing them involves using the phone.
i mentioned this in another post but worth pointing out again - one of their lines, “Lorem ipsum docet” means “Pain itself teaches.” There’s failsafe text in Deltarune which could be a reference to this dialogue (and comes part of a little poem that might be about Mystery Man/Gaster): “The pain itself is reason why.”