Mulligans
General Mulligans
Phase Stalker is always valuable in starting hand. If you start with this consider a Mulligan to remove all secrets from hand.
Scavenging Hyena is good if you can Mulligan for Springpaw, Unleash the Hounds, and Snake Trap.
Hyena Alpha is higher cost but only 4 mana. It's on the higher end of your deck with Savannah Highmane so knowing that board presence is in hand is nice.