Volcano Hellion
Creature — Hellion
This creature has echo 
, where X is your life total. (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, it deals an amount of damage of your choice to you and target creature. The damage can't be prevented.
Wayne Reynolds
Planar Chaos (PLC)
• #111Rulings
As Volcano Hellion's "enters" ability resolves, you choose a number. Volcano Hellion deals that amount of damage to you and to the targeted creature. You may choose 0.
(wotc • 2007-02-01)
Volcano Hellion's echo cost constantly changes; it's not locked in when it enters. The echo cost you pay is equal to your life total as the echo triggered ability resolves.
(wotc • 2007-02-01)
Rulings
As Volcano Hellion's "enters" ability resolves, you choose a number. Volcano Hellion deals that amount of damage to you and to the targeted creature. You may choose 0.
(wotc • 2007-02-01)
Volcano Hellion's echo cost constantly changes; it's not locked in when it enters. The echo cost you pay is equal to your life total as the echo triggered ability resolves.
(wotc • 2007-02-01)