Misunderstood Trapeze Elf

Card text

{TK}{TK} — Whenever you cast a spell, this creature gets +X/+X until end of turn, where X is the amount of generic mana in that spell's mana cost.

{TK}{TK}{TK} — Hexproof

{TK}{TK} — 4/2

{TK}{TK}{TK}{TK} — 6/6