Bronto

Earthen Resilience (1/day). If Bronto fails a saving throw, he can choose to succeed, but he drops any creatures he was grappling and can't use the No! reaction until the start of his next turn. 

Relentless (1/Turn). When the rampart isn’t incapacitated and they are reduced to 0 hit points but not killed outright, they can make an attack against a hostile creature (no action required) before the hit point reduction is resolved. If the attack hits and its damage reduces the target to 0 hit points, the rampart drops to 1 hit point instead of 0 hit points.

Multiattack. Bronto makes two Fist attacks. If Bronto targets the same creature with both attacks, the target has disadvantage on attack rolls against creatures other than him until the start of his next turn. Bronto can make a Between a Rock attack in place of one of those attacks.
Fist. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 7 (2d6 + 4) bludgeoning damage.
Between a Rock... Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 7 (1d6+7) bludgeoning damage, and the target creature must succeed on a DC 17 Strength saving throw or become grappled, when grappled in this way they are also considered restrained. The target creature can use their action to make a Strength (Athletics) or Dexterity (Acrobatics) check to attempt to escape the grapple on their turn. While grappling a creature in this way, Bronto can make one less Fist attack. Bronto can grapple up to two creatures in this way. 
Tackling Charge. Bronto charges in a 10-foot by 30-foot line. Creatures in the area must make a DC 17 Dexterity saving throw or take 10 (3d6) bludgeoning damage and become grappled by Bronto. They are brought to a 5-foot space adjacent to Bronto at the end of his movement. They are knocked prone. 

...And a Hard Place. Bronto can make a Fist attack against a target he is grappling, when grappling two creatures, he attacks them by slamming them together.  

No!  When a creature within 5 feet of Bronto targets another creature with an attack, the attacker must target him instead.