i accidentally skipped the first mome beast in an otherwise very bad run, here's a vid:

i tried to see if i could find a way to do this consistently, but i couldnt figure anything out. as far as i can tell, the mome beast usually travels in a direct line towards you but occasionally just moves in a random direction. i dont think the space where you encounter it is big enough for there to be any way to dodge it consistently unless you get lucky. i'll experiment with it a bit more tho

Now all we gotta do is find a reliable way to pull it off.

I did some extensive testing on this back when I was still doing runs and managed to get it maybe once or twice out of a few hundred tries. As far as I could tell, it's just some weird quirk in RPG Maker's follow AI that randomly causes it to go off path like that, pure RNG and not something that can be easily or reliably manipulated. My testing was done on an edited copy of the game, though, with Phillip's start position set to right before the screen transition, so it's possible that something done in the earlier game on a normal run can affect this.