ToxicToxic is a static ability. It is written “toxic N,” where N is a number.
Some rules and effects refer to a creature’s “total toxic value.” A creature’s total toxic value is the sum of all N values of toxic abilities that creature has.
Combat damage dealt to a player by a creature with toxic causes that creature’s controller to give the player a number of poison counters equal to that creature’s total toxic value, in addition to the damage’s other results. See rule 120.3. (CR 702.164) 1 (Players dealt combat damage by this creature also get a
poison counterA player with ten or more poison counters loses the game. (CR 704.5c).)
When this creature
diesIs put into a graveyard from the battlefield. (CR 700.4),
proliferateTo proliferate means to choose any number of permanents and/or players that have a counter, then give each one additional counter of each kind that permanent or player already has.
In a Two-Headed Giant game, poison counters are shared by the team. If more than one player on a team is chosen this way, only one of those players can be given an additional poison counter. The player who proliferates chooses which player that is. See rule 810, “Two-Headed Giant Variant.” (CR 701.34). (Choose any number of permanents and/or players, then give each another
counterTo counter a spell or ability is to cancel it: remove it from the stack without resolving it. A counter on an object or player is instead a marker that changes characteristics or interacts with rules or abilities; for example, a +1/+1 counter modifies a creature’s power and toughness. (CR 701.6; 122.1) of each kind already there.)