Parents: Charizard + Aggron
Shared egg group: Monster
Offspring name: Aggrizard
New type: Steel/Fire
New base stats: 84/107/139/95/83/85
New ability and desc: Burning Head/Ghost Rider - avoids recoil damage and boosts fire moves by 1.5x if using a contact/recoil move.
Notable moves: Dragon Dance, Swords Dance, Rock Polish, Earthquake, Crunch, Outrage, Dragon Claw, Hone Claws, Stealth Rock, Defog, Roost, Flare Blitz, Head Smash, Hone Claws, Iron Head, Heavy Slam, Aqua Tail, Surf, Fire Blast, Boltbeam, Thunder Punch & Ice Punch, Autotomize (if not using Heavy Slam), earth power, Flash Cannon, Taunt, Will O Wisp...
Role identification: Reserving It's interesting how Charizard never seems to lose much of its SpA when fused. Anyway, statistically, it's more or less a physical heatran, except it gains moves from two mons with very good movepools, and a plethora of different roles to choose from. BTW, if that 1.5x for fire moves seems ludicrously powerful, here's my idea: to make it so that all moves that initiate body contact (head smash/heavy slam) will include additional damage accounting for the fire type, like flying press. Other than that, fairly standard.
Parents: Charizard + Aggron
Shared egg group: Monster
Offspring name: Aggrizard
New type: Steel/Fire
New base stats: 84/127/139/145/113/85
New ability and desc: Drought
Notable moves: Dragon Dance, Swords Dance, Rock Polish, Earthquake, Crunch, Outrage, Dragon Claw, Hone Claws, Stealth Rock, Defog, Roost, Flare Blitz, Head Smash, Hone Claws, Iron Head, Heavy Slam, Aqua Tail, Surf, Fire Blast, Boltbeam, Thunder Punch & Ice Punch, Autotomize (if not using Heavy Slam), earth power, Flash Cannon, Taunt, Will O Wisp...
Role identification: Outstanding, tanky wallbreaker, with decent bulk to carry out defensive sets. Yes it doesn't have Flash Fire like Heatran, but both its regular form's ability and Drought compensate for it. While it hits less harder than Mega Charizard Y, it can take more hits, gets neutral damage from SR, and generally stays alive longer. Can also abuse a defensive set with Roost and Lava Plume/WoW.
Parents: Charizard + Aggron
Shared egg group: Monster
Offspring name: Aggrizard
New type: Steel
New base stats: 84/137/189/95/103/85
New ability and desc: Filter
Notable moves: Dragon Dance, Swords Dance, Rock Polish, Earthquake, Crunch, Outrage, Dragon Claw, Hone Claws, Stealth Rock, Defog, Roost, Flare Blitz, Head Smash, Hone Claws, Iron Head, Heavy Slam, Aqua Tail, Surf, Fire Blast, Boltbeam, Thunder Punch & Ice Punch, Autotomize (if not using Heavy Slam), earth power, Flash Cannon, Taunt, Will O Wisp...
Role identification: Yes, it is less bulkier than regular Aggron. But it has Dragon Dance with 85 speed, and even Double dance, and nice mixed bulk to set up for it, and not to mention, ROOST! I believe it can perform a defensive role much better than Mega Aggron, who is a straight up tank. It can perform offensive roles much better in lieu of better speed and boosting moves.
Parents: Charizard + Aggron
Shared egg group: Monster
Offspring name: Aggrizard
New type: Steel/Dragon
New base stats: 84/153/172/116/83/85
New ability and desc: Tough Claws
Notable moves: Dragon Dance, Swords Dance, Rock Polish, Earthquake, Crunch, Outrage, Dragon Claw, Hone Claws, Stealth Rock, Defog, Roost, Flare Blitz, Head Smash, Hone Claws, Iron Head, Heavy Slam, Aqua Tail, Surf, Fire Blast, Boltbeam, Thunder Punch & Ice Punch, Autotomize (if not using Heavy Slam), earth power, Flash Cannon, Taunt, Will O Wisp...
Role identification: This is scary. REAL scary. It's held back by its speed, but Dragon Dance solves that. Your best bet is to bring a scarf with special STAB moves that this is weak to. Offensively, it should be a beast, with Dialga's formerly unique typing. And it has great physical defense to boot. It can even perform a tanking role.