Hatebears are inexpensive creatures that attack while simultaneously disrupting an opponent's strategy. Their effects commonly tax spells, limit searching, interfere with graveyards, or otherwise make normal game actions less efficient.
Archon of Emeria restricts players to one spell each turn, Collector Ouphe shuts down many artifact abilities, and Leonin Arbiter taxes library searches. Hatebears decks combine several small annoyances until opponents discover their deck can barely function.