Bite and tail have different tells
Venom Bite draws the neck back before snapping for 4 piercing damage and Poison. Tail Smack winds up the tail; the mouth closes shortly before impact. That attack deals 5 and can lower your ATK.
Growl is a speed buff
The opening sequence is Venom Bite → Growl → Tail Smack, then alternating bite and tail attacks. Growl gives Fast for three turns. Prepare for the extra enemy actions rather than treating the roar as a wasted move.
Story fight and Floor 29
The Rugged Rainforest boss has 20 base HP and Mobile. Floor 29 contains multiple Komodo Dragons, so a single-target story script does not cover all incoming attacks there. Remove one dragon to reduce the number of active attackers, while keeping enough recovery for Poison already applied.