creep up on

[creep up on] {v.} 1. To crawl towards; move along near the ground; steal cautiously towards so as not to be seen or noticed.

The mouse did not see the snake creeping up on it over the rocks.

Indians were creeping up on the house through the bushes.

2. or [sneak up on] To come little by little; arrive slowly and unnoticed.

The woman's hair was turning gray as age crept up on her.

Winter is creeping up on us little by little.

The boys didn't notice the darkness creeping up on them while they were playing.

Compare: COME OVER.