The challenge this week is to battle with Lava Spider, and for me that was a bit of a challenge as this is not a unit that often fits in my teams. However, Quix had his orders so he did what he could. Sadly, both battles where he found a slot for the spider were against FWA bots. In the first battle he would have won even without the Lava Spider, so we'll skip over that one.
The Battle
Positioning
In this battle the Lava Spider served to absorb damage from the enemy sniper and do a bit of auxiliary damage. This positioning in front of the Fire Elemental allowed it to keep the Elemental alive to continue doing blast damage to the enemy second row tank.
As you can see, by Round 2 the two tanks were disposed of, and the rest of the team won't last long
Conclusion
Lava Spider at level 1 does only one damage and is quite slow. However, the Mana cost is only 3 and the 4 health points are quite substantial. You may find a place for it to protect the bigger ranged DPS from snipers and sneakers while adding its bit to the total damage.