At the beginning of combat on your turn, put a +1/+1 counter on target creature you control. Then if that creature has three or more +1/+1 counters on it, transform Hadana's Climb.
(Transforms from Hadana's Climb.)
: Add one mana of any color.
, : Target creature you control gains flying and gets +X/+X until end of turn, where X is its power.