killer beat

Killer beat is referring to as the beat is a banger beat or best beat ever made

Usually it is made for rap mostly

(killer beat) The beat is used to throw in some tight hot rhymes, best metaphors and dope punchlines

mountain killer

Person who habitually chooses the same ascent route on a mountain, chipping at its face more each time, thereby destroying more of the mountain on a climb.

Richard, why not use another route to climb that mountain? Leave that route so others can enjoy it. You're a mountain killer!