First, an explosion of fire on the ground. Then, an explosion of laughter in the trees.

Simian Spirit Guide

"It's rarely worth questioning where the mana comes from. Just be grateful."
—Jaya Ballard, task mage

Mystery Booster 2

Exile Simian Spirit Guide from your hand: Add {R}.

Secret Lair Drop

Time Spiral Remastered

"All my spells smell like burnt hair lately."
—Jaya Ballard, task mage

The List

If a spell or ability's cost includes returning a creature to your hand and paying mana, you can't activate Simian Spirit Guide's mana ability after returning it to your hand. This is because mana abilities must be activated before you begin paying costs.