[mwcard=MW1C16]Flaming Hellion[/mwcard] [mwcard=DNC16]Spitting Raptor[/mwcard]
On the first Look these two creatures are very similar. Both are Level 3, have the same Stats (9 Life, 2 Armor), roll the same attack dice. They are some kind of mix between Melee endurance (See Westlock Knight with more HP, more Armor, Defense) and Archer Ability (See Royal Archer with more Range and less Armor)
Thus they are taking a niche spot and are very versatile.
Now for the difference. The Raptor melee attacks with a Piercing +1 bonus. This gives your a garanteed Bonus on your attacks as long as you attack an armored target. If your target has no armor, you wont get anything. His ranged ability (without minimal range btw.) can be used to attack targets in the air and - more important - reduce armor of a target on 5+ for 1 Corrode. So he would probably use his ranged attack to weaken a target for all your other attack sources, but after that - if the target has no more armor left - his own Piercing attack is weaker than before. In that situation both of his attacks are almost the same: 3 dice with direct corrode Damage on 5+ against 4 dice melee attack.
Your Raptor can become your Pet if you play the Straywood Beastmaster. That makes him very durable, but only buffs his melee strength ... and it seems there are better choices for the same mana, if you want a badass melee pet.
The Hellion on the other side costs 2 more mana to summon and comes into play with the important flame immunity trait, that makes him almost unkillable for Adramelech Warlock solo mages. Both of his attacks are fire based can cause severe burn damage (up to 2 burns), while the ranged attack has a slightly better chance of applying them (Akiros Favor is always a good thing with the Hellion). This means, that his attacks can be easily strengthened or weakened by several effects and items in the game (Smoldering Curses, Dragonscale Hauberk, Elemental Cloak). That being said, the Hellion can deal more damage to your enemies, if they aren't resistant to Fire damage. This hellish creature needs your assistance, so if you bring the Hellion into the battle, be sure to have ways to remove any Fire Resistance of the enemy or else you won't have fun with him.
Your Hellion can become your Blood Reaper, when playing he Arraxian Crown Warlock. This only pimps his melee attack strength (not his durability) and you might be hindered to use his ranged attack while under the influence of Bloodthirsty.
In the end the Raptor seems to be the more solid choice, because his ability to deal damage is not that dependent on other circumstances. The Hellion on the other side is the creature with the better damage spikes, both good and bad.