SkulkSkulk is an evasion ability.
A creature with skulk can’t be blocked by creatures with greater power. (See rule 509, “Declare Blockers Step.”)
Multiple instances of skulk on the same creature are redundant. (CR 702.118) (This creature can't be blocked by creatures with greater power.)
This creature enters with X +1/+1
countersTo 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) on it.
At the beginning of your upkeep, if this creature has one or more +1/+1
countersTo 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) on it, you may remove a +1/+1
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) from it. If you do, draw a card.