Sliver creatures you control have "When this creature enters, it deals 1 damage to target player or planeswalker and you gain 1 life."
Illustrated by Mark Behm · Jumpstart: Historic Horizons · #701
There are no rulings for Lavabelly Sliver.
Sliver creatures you control have "Whenever this creature is dealt damage, it deals that much damage to target player or planeswalker."
Hellbent — As long as you have no cards in hand, Sliver creatures you control have ": This creature deals 1 damage to target player or planeswalker."
Landfall — Whenever a land you control enters, you may have this creature deal 1 damage to target player or planeswalker.
When this creature enters, return a red or green creature you control to its owner's hand.
When this creature enters, it deals 1 damage to target player or planeswalker.
When this creature enters, it deals damage to target player or planeswalker equal to the number of Humans you control.
When this creature enters, you get (four energy counters).
, Pay : This creature deals 1 damage to target creature.
, Pay eight : This creature deals 6 damage to target player or planeswalker.