The 4-turn, 11-action solution for Dinosize on Ironbark Treant is still good, too.
EDIT: 10 actions, now I’m looking at it. Don’t recruit Merfolk Prospector, skip both attacks on Turn 2, Turn 3 without the Dinosize, and cast RG and both Dinosizes on Turn 4.
Zane + Red starrer can do it turn 3 as player 1 in 14 actions:
Turn 1
- Zane
- Attack for 2
- Rambaster
- Attack for 3 (5 total)
Turn 2: - Bombaster
- Pillage 2 gold (7)
- Bloodrage Ogre
- Zane hits bunny
- Attack for 3 (10)
Turn 3 - Scorch bunny
11-14. Attack for 3 + 3 + 2 + 2 (20)
Seems like there should be a line using drakk mid or max to get faster or equal, but I don’t see it. You also spent 10 of your 12 gold, for what that’s worth.