Fire Absorption. Whenever the giant strider is subjected to fire damage, it takes no damage and regains a number of hit points equal to half the fire damage dealt.
Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit:8 (1d8 + 4) piercing damage.
Fire Burst (Recharge 5–6). The giant strider hurls a gout of flame at a point it can see within 60 feet of it. Each creature in a 10-foot-radius sphere centered on that point must make a DC 12 Dexterity saving throw, taking 14 (4d6) fire damage on a failed save, or half as much damage on a successful one. The fire spreads around corners, and it ignites flammable objects in that area that aren't being worn or carried.
In regions that contain hot springs, volcanic activity, or similar hot and wet conditions, firenewts might be found. These humanoid amphibians live in a militaristic theocracy that reveres elemental fire in its worst incarnation.