Yes but Otyugh can be nerfed by a single Drain Life thats the difference. thus the you can't lower Attack comment above. This card is good but can't really be compared to Otyugh.
The easiest comparison is Maxwells Demon which is 3|2 for 5
and the ability costs 2
for an instant kill again with conditions. The upgrade gains more defence but stays at the same costs.
SO in saying that you card starts at 5
This isn't bad. The difference is the high Hp, taking it out of range of every creature control card except Rage Potion. The Maxwells is 2 Hp which means it can be nerfed quickly. Your ability costs 3
which is a greater cost, this is good as your creature now can kill any of the small creatures that Maxwells can't.
I think your upgrade should gain one cost though and be a 5|4 creatures. In other words no more benefit to attack and ability just a greater chance to stay in the battle.
I hope this helps somewhat.
Scyther