Spike Feeder is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

This creature enters with two +1/+1 counters on it. , Remove a +1/+1 counter from this creature: Put a +1/+1 counter on target creature. Remove a +1/+1 counter from this creature: You gain 2 life.

Complete guide

Spike Feeder is a classic green creature that showcases the versatility of the Spike creature type. By entering the battlefield with +1/+1 counters, it serves as a flexible tool for both life gain and creature enhancement. Understanding how to manage its resources is key to mastering its place on the board.

What It Does

Spike Feeder is a 0/0 creature that enters with two +1/+1 counters. It features two activated abilities: one that transfers its power to another creature for two mana and another that converts its counters directly into life for no mana cost. Because its toughness is derived entirely from counters, removing the last counter will cause it to be put into the graveyard for having 0 toughness.

How It Resolves Step by Step

When you cast Spike Feeder, it enters the battlefield with its counters already on it. To activate an ability, you choose which one you want and pay the cost—this includes removing the counter as a part of the activation. If you choose to gain life, the ability goes on the stack and you gain 2 life once it resolves. If you choose to move a counter, you must select a target creature; upon resolution, that creature receives a +1/+1 counter.

Common Mistakes

A frequent error is trying to remove a counter to gain life while Spike Feeder is the target of a lethal spell, only to realize that removing the final counter kills it before the spell even resolves. Additionally, remember that the life gain ability does not require mana, whereas moving a counter costs two mana. You cannot move a counter to Spike Feeder itself to 'save' it, as the ability requires removing a counter first.

When to Play It

Spike Feeder is best utilized in decks that can proliferate counters or benefit from repeated life gain. It acts as a defensive roadblock that can be 'cashed in' for 4 life at any time, even in response to a board wipe. It is also excellent for shifting power to an unblocked attacker to surprise your opponent with extra damage.

Interaction examples

The Ultimate Defensive Block

Solemn Simulacrum

If your opponent attacks with Solemn Simulacrum, you can block with Spike Feeder. Before damage is dealt, you can activate Spike Feeder's ability twice to remove both +1/+1 counters and gain 4 life. Spike Feeder will then die due to having 0 toughness, but the Solemn Simulacrum remains blocked and deals no damage to you.

Boosting Your Utility Creatures

Sakura-Tribe Elder

You have both creatures on the battlefield. You pay {2} and remove a +1/+1 counter from Spike Feeder, targeting Sakura-Tribe Elder. Once the ability resolves, Sakura-Tribe Elder becomes a 2/2. This allows your utility creature to survive small board pings or trade with larger threats before you eventually sacrifice it to search for a land.

Guide written with AI from the official text and rulings. Official English text prevails.