"Frenzied Metabolism" isn't a standard Magic keyword—it appears to be a card name rather than an evergreen or keyword ability. Without the specific card text in front of me, I can't reliably explain its exact rules function, and I'd rather not invent mechanics that could mislead your deckbuilding.
If you can paste the full Oracle text (the rules box of the card), I'll break down exactly what it does, the timing or targeting nuances people commonly misplay, and how it performs in a Commander pod. Cards with "metabolism" or "frenzy" themes often involve life-gain payoffs, sacrifice triggers, or aggressive combat bonuses, but I don't want to guess at the specifics.
Drop the card text and I'll give you the concise, accurate rundown you're looking for.