Tiamat

Flying
When Tiamat enters the battlefield, if you cast it, search your library for up to five Dragon cards not named Tiamat that each have different names, reveal them, put them into your hand, then shuffle.

Owlbear

Trample
Keen Senses — When Owlbear enters the battlefield, draw a card.

Flumph

Defender, flying
Whenever Flumph is dealt damage, you and target opponent each draw a card.

Baleful Beholder

When Baleful Beholder enters the battlefield, choose one —
• Antimagic Cone — Each opponent sacrifices an enchantment.
• Fear Ray — Creatures you control gain menace until end of turn. (A creature with menace can't be blocked except by two or more creatures.)