For the eruption:
* The volcano erupted like a giant, fiery geyser.
* The volcano spewed lava like a dragon breathing fire.
* The volcano roared like a beast awakened from its slumber.
* The volcano's eruption was as sudden and powerful as a lightning strike.
For the volcano's form:
* The volcano stood like a giant, sleeping giant.
* The volcano was as imposing as a mountain fortress.
* The volcano's cone was as symmetrical as a perfectly sculpted pyramid.
* The volcano's crater was like a gaping maw, waiting to unleash its fury.
For the volcano's effect:
* The volcano's ash cloud was as thick and suffocating as a blanket of smoke.
* The volcano's destruction was as devastating as a hurricane.
* The volcano's lava flow was as relentless as a tidal wave.
The best simile will depend on the specific context and the aspect of the volcano you want to emphasize.
