Magma Sliver 
Creature — Sliver
All Slivers have "
: Target Sliver creature gets +X/+0 until end of turn, where X is the number of Slivers on the battlefield."
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL