As we know, the Pumpkin Bot mount is complete garbage. It has a slow walkspeed, shitty guns that can't hit anything past 20 studs, and is only useful for the slightly higher jump height. As such, I suggest a buff, and to balance it out with the other mounts, adding abilities / features for them too. This will hopefully make mounts worth using other than for just faster walkspeed.
Pumpkin Bot's stats after the buff would look like this:
Speed: 18
Jump: 72
Damage: 30
Ammunition: 120 (Can be refilled at an ammo station, but each reload would only give you 60 rounds, so you would need 2 reloads to refill it fully)
Accuracy: 120
Range: 80
As for the other 2 mounts, I have some ability ideas for them.
Rhino's ability would be a charging one, similar to the Rhi-Snow boss itself. Upon pressing F while riding on the mount, the Rhino will charge at a set speed of 32. It only moves in the direction you intially were facing, and you cannot change it's direction while under the ability. Anybody hit in the charge will be dealt 40 damage and will be tripped. The charge will stop either when the player hits something, the player dies, or the M key is pressed. This ability has a cooldown of 35 seconds.
Crab's ability would be a defensive one. Upon pressing F, the Crab and the user would "shell" themselves. In "shell" mode, the user is immune to all forms of damage for 5 seconds, however, the user and the crab are completely frozen and the user cannot equip any weapons or items. When "shell" mode is over, the user is able to move and equip items again. It is important to know that the user cannot cancel the "shell" mode when they want to, as dismounting is disabled in shell mode, so you should only go into shell mode when you know you need to. This ability has a cooldown of 40 seconds.
Let me know what you think of these ability ideas and the buff for Pumpkin Bot in the comments below. If you like the sound of this, give it a kudos. Till next suggestion, I'm AAGBS and I'm still running out of ideas.