Goblin Adventurers

At the beginning of each upkeep flip a coin;
On Heads, Goblin Adventurers gain Mountainwalk until end of turn.
On Tails, Goblin Adventurers gain Menace and " Creature must attack each turn if able" until end of turn.
Wallwalk (If an opponent controls a wall Goblin Adventurers cannot be blocked by that opponent.)