Fire lizard
Fire lizard is a scaled shape of living fire. A Pyre summoning, Summon fire lizard, calls it out of the Welter, and Pyre holds its shape. It burns whatever it touches, and fire cannot hurt it. Its scales turn most blows aside. Cold is the only thing it dreads.
Mana sustains it, and its card sets a keep in geld as well. Withdraw the mana and it cools to nothing. Its lord may do so at any time.
It fights hardest against treefolk, such as Tree guardian and Strangling ivy, and Bloom lords learn to fear it. Pyre cultivators see no malice in it. Ash nourishes growth, so Pyre feeds Bloom, and they call the fire-lizard the first spark of that turning: it burns the old wood so that the new may grow. The treefolk are not comforted.