Play Thorim and choose the Oracle Morgl (murloc tier 7), and then play a Hackerfin with Morgl in your warband, not hand.
Note that Morgl’s stats do not increase, even though he has the “Poisonous” keyword.
Apparently, Poisonous is not a bonus keyword.
Only Divine Shield, Reborn, Stealth, Taunt, Venomous, and Windfury are bonus keywords.