oops my comp. glitched out i might be posting this again, but idk
here are some ideas for pyralis
cow/mooshroom equivilants (Hellcow [normal cow, gives off torch particle effect, red-ish, milk for lava] and Wartcattle [nether mooshroom, instead of red mushrooms, has netherwart growing from it, when sheared turns into Hellcow])
a form of parasite sort of like a sliverfish (Nethertick [hides in netherrack, when mined summons friends, gives player poison or Withering to simulate sucking your blood])
Nightmare horses (gives off torch particle effect, can run on lava)
Hellhound dogs (gives off torch particle effect, sets foes on fire, tamed with charcoal or rotten flesh)