|“||But Hiccup said it was a passing Tigerbreath who has done it, and Stoick was so smug with pride and a full belly that he believed him.||”|
|— The Day of the Dreader|
There is no description or images for this dragon species. One can assume a Tigerbreath is not very large, because if it had been true, it might have burned their whole hut down. It might also be inferred that it has stripes, based on the 'tiger' in its name.
Hiccup mentions an incident where he tried to cover for Toothless - who had burned up a few things in their home - by blaming it on a passing Tigerbreath. His father Stoick believed him because of a full and satisfied belly.