Thanks for the feedback, although I still think the lore stands up to scrutiny for the following reason:

I'm not sure if Hugh's explanation at the start ascertained if the creature "always" has to walk given that the adolescents themselves don't much about it. There was also another instance in the movie where the creature remains stationary for a brief period of time as you mentioned. In addition to the fact that the creature walking "all the time" simply couldn't work on a logical level *(e.g. obstacles, etc).

Nonetheless, interesting observation, bud. :)