other pests, bats, insects, snakes, and spiders you control get +1/+1.
when blex, vexing pest dies, you gain 4 life.
//
search for blex 2bb
sorcery
look at the top five cards of your library. you may put any number of them into your hand and the rest into your graveyard. you lose 3 life for each card you put into your hand this way.
Pests are typically harvested before they outgrow their enclosures. Blex is far from typical.