This is Gundam Physalis variant / modified version by shy0221 pepakura designer.
When I say variant, the model is based on Physalis and RX-78GP02A Gundam GP02A (Type-MLRS) however the designer add a bit of his own design into this model.
If you see the original model should be a bit fat, while RX-78GP02A Gundam GP02A (Type-MLRS) is a bit slimmer but the design on the rocket and some parts of armor has a slight different than the two models.
But it’s still a physalis so he gave it the name Gundam Physalis. Physalis is designed by the Earth Federation for attacking enemy bases or to provide mid-range support for friendly forces