# 2020 Magic: The Gathering Magic Online Promos #80977

> The 2020 Magic Online Promos Cavern Whisperer foil promo is a Common Nightmare creature card featuring mutate mechanics and menace.

Canonical URL: https://supercatch.com/product/magic-the-gathering-magic-online-promos-cavern-whisperer-80977-foil-promo

## Identity

- **Year**: 2020
- **Brand**: Magic: The Gathering
- **Set**: Magic Online Promos
- **Card Number**: 80977
- **Featured**: Cavern Whisperer
- **Game**: Magic: The Gathering
- **Rarity**: Common
- **Mana cost**: {4}{B}
- **Type**: Creature — Nightmare
- **Power / Toughness**: 4 / 4
- **Color**: B
- **Language**: English
- **Material**: Card Stock
- **Finish**: Foil

## Description

The 2020 Magic Online Promos Cavern Whisperer foil promo is a distinct entry in the Magic: The Gathering catalog, identified by card number 80977. Released as part of the Magic Online Promos series, this Common rarity card carries a Black mana cost of {4}{B} and functions as a Creature — Nightmare with 4 power and 4 toughness. The foil treatment gives this promo variant a shimmering finish that distinguishes it from the non-foil base prints within the set.

Gameplay-wise, Cavern Whisperer utilizes the mutate mechanic, allowing players to cast it for {3}{B} to place it over or under a target non-Human creature they own. This interaction combines the abilities of both creatures, creating a synergistic board presence. The card also possesses the menace keyword, meaning it requires two or more creatures to block it effectively. A key strategic feature is its triggered ability: whenever Cavern Whisperer mutates, each opponent must discard a card, providing a potent advantage in resource management.

Designed by Steve Ellis, this card appeals to collectors who track specific promo releases and players who utilize mutate strategies in constructed formats. The Magic Online Promos set serves as a unique archive for digital-exclusive cards, making items like the Cavern Whisperer foil promo a notable piece for those cataloging the breadth of Magic Online’s promotional history. Whether building a thematic collection of Nightmare creatures or focusing on the mutate archetype, this card offers both mechanical depth and catalog significance for dedicated Magic: The Gathering enthusiasts.

## FAQ

### What is the mana cost of Cavern Whisperer?

Cavern Whisperer has a mana cost of {4}{B}, requiring four generic mana and one black mana to cast from the hand. If cast for its mutate cost, it requires {3}{B} instead.

### How does the mutate mechanic work on this card?

When Cavern Whisperer is cast for its mutate cost, it can be placed over or under a target non-Human creature you own. The resulting permanent becomes the creature on top plus all abilities from the creatures underneath it.

### What is the card number for Cavern Whisperer in Magic Online Promos?

The Cavern Whisperer promo card is listed as card number 80977 in the Magic Online Promos set, which was released in 2020.

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Editorial content updated: 2026-10-10.

Site deployment: 2025-11-29.